SL55 AMG - Sympatico Personal Webspace

Mercedes-Benz SL55 AMG - DIY & Parts Cross-References, etc.
Disclaimer : This collection of info, links, etc., does not imply any endorsement or guarantee of fitness of a given
product or service producer, and also may be subject to errors or omissions. If I have made any mistakes, or if
you wish to contribute related info, please contact me.
Overview
Mercedes seem to have created the perfect car. Superb(ish) quality, gorgeous
looks, super car performance and at the touch of a button it becomes a convertible!
The V8 engine from the SL500 has been heavily modified by AMG resulting in a
near 50% increase in power. This is enough to propel the SL55 to over 200mph
with speed restrictor removed.
Braking is excellent thanks to 8-pot vented discs and ESP brake by wire
technology, while the SL55 becomes the first Mercedes to feature pushbutton
sequential gear shift. Handling is assisted by state of the art active body control,
however it still struggles to cope with the car's enormous 2 ton mass.
With the SL55 AMG, Mercedes has taken its legendary roadster and injected it with
a major dose of horsepower that elevates it to near super car status. With nearly 500 horsepower emanating
from its supercharged V8, this drop top can outdo most sports cars in a straight line, yet it's still docile enough to
go for a top-down Sunday drive. The ridiculously powerful SL65 AMG might overshadow the SL55 in the minds
of some buyers, but unless you have regular access to roads resembling the German autobahn, the real-world
performance difference will go unnoticed 95 percent of the time. If you're looking for the ultimate combination of
open-air fun and unparalleled performance, the SL55 satisfies in ways few other cars can.

Details
Construction
• Bonnet/hood! aluminium
• Boot/trunk lid! aluminium
• Front wings/fenders! aluminium
• Doors! ! aluminium
• Inner door shells! magnesium!
Engine
Engine Handcrafted by! ! Florim Avdija, AMG Affalterbach, Germany
Bore x Stroke! ! ! 97.00 mm x 92.00 mm
Power! ! ! ! 494 bhp @ 6,100 rpm
Torque! ! ! ! 516 lb/ft @ 2,750 to 4,000 rpm
Maximum RPM!! ! 6,500 rpm
Firing Order! ! ! 1-5-4-2-6-3-7-8
Compression Ratio! ! 9.5:1
Supercharger Max. Boost! 0.8 bar (12 psi)
Air Filter Element! ! K&N 33-2181 (2 required) +15hp
Oil Filter
Oil! ! ! ! Mobil 1 10W30 Fully Synthetic (9.0 US qt (8.5 litres)
Spark Plugs! ! ! NGK PFR 5 R-11 (these are Platinum)
Spark Plug Gap ! ! 0.039 in (1.0 mm)
Spark Plug Torque! ! 15 – 22 lb/ft (20 – 30 Nm)
In-Line Fuel Filter
Poly-V-Belts! ! ! 2 belts (Length 8ft 1 in (2462 mm) and 4 ft 3 in (1289 mm))
Cooling System!Anti-Freeze! MB 320.0 anticorrosion/antifreeze with water 50:50

Transmission
Gearbox! ! ! 5-speed Auto
Ratios! ! ! ! 1st-3.59; 2nd-2.19; 3rd-1.41; 4th-1.00; 5th-0.83
Gear Oil! ! ! MB Automatic Transmission Fluid (9.1 US qt (8.1 litres))
Final Drive! ! ! ! !
Ratio! ! ! ! 2.82 : 1
Oil! ! ! ! Hypoid Gear Oil SAE 85 W 90 (1.5 US qt (1.4 litres))
Suspension
Front! ! ! ! Double Wishbones and Coil Springs with ABC (Active Body Control)
Rear! ! ! ! Five-link with ABC (Active Body Control)
Steering
Type! ! ! ! Power assisted, rack and pinion
Ratio
Turn Lock to Lock
Turning Circle! ! ! 36.2 ft
Power Fluid! ! ! MB Power Steering Fluid (Pentosin CHF 11S)
Braking System
Front! ! ! ! Brembo Ventilated 14.2” Discs with 8 piston fixed-type callipers
Rear! ! ! ! Brembo Ventilated 13.0 in Discs with 4 piston fixed-type callipers
Master Cylinder!! ! Servo-assisted master cylinder
Fluid! ! ! ! Mercedes-Benz DOT 4+

Described! ! ! Electronically controlled 4-circuit with 4-wheel discs.
Sensotronic Brake Control! Electronic braking system transmits brake pressure individually to
! ! ! ! each wheel based on driver input and various vehicle parameters.
! ! ! ! Sensotronic optimises brake pressure at each wheel in normal
! ! ! ! braking, emergency stopping and during ESP activity. “Soft Stop”
! ! ! ! feature precisely modulates brake pressure as the car approaches a
! ! ! ! stop during normal braking. Automatic brake drying applies the
! ! ! ! brakes lightly and briefly based on windscreen wiper use and driver
! ! ! ! braking intervals, to reduce moisture on the brake surfaces.
! ! ! ! Predictive brake priming sets the brake pads nearer the discs when
! ! ! ! the driver quickly releases the accelerator, for faster braking
! ! ! ! response.
Brake Assist! ! ! System senses emergency barking via the speed at which the driver
! ! ! ! presses the brake pedal and immediately applies maximum available
! ! ! ! braking force, potentially reducing the overall stopping distance by
! ! ! ! eliminating the delay caused by a common human tendency, not to
! ! ! ! brake hard enough, soon enough. Letting up on the brake pedal
! ! ! ! releases “Brake Assist”.
Antilock Braking System! ABS senses impending wheel lockup under heavy braking and
! ! ! ! pumps the front brakes individually or the rear brakes together (to
! ! ! ! help to maintain stability) as needed, up to 30 times per second, to
! ! ! ! prevent lockup and maintain steering ability. Sensotronic eliminates
! ! ! ! the pedal pulsation commonly associated with conventional brake
! ! ! ! systems and ABS.
Electrical
Alternator! ! ! ! 14 V / 180 A
Starter Motor! ! ! ! 12 V / 1.7 kW
Starter Battery! ! ! ! 12 V / 35Ah
Consumer/Accessory Battery! ! 12 V / 70Ah
Wheels
PCD! ! ! ! ! 5 x 112 mm
Centre Bore! ! ! ! 66.6 mm
Std. M.B. Wheel Bolts! ! ! M14 x 1.5” thread pitch, Ball Seat, Thread Length - 25 - 28mm
Standard Original
AMG ultra-thin-spoke, light alloy, wheels (Style V)
Front ! ! 8.5" x 18" ! ET 30 mm! 255/40 R 18
Rear ! ! 9.5" x 18" ! ET 33 mm! 285/35 R 18
Note :
• Mercedes-Benz wheel bolts have a “Ball Seat”, while most aftermarket wheels require bolts with a “ 60
degree Taper Seat”
• Higher positive ET/offset = more”set-in”. (i.e. if original has ET 38, and new has ET 28, then new wheel
will sit further out by 10 mm, and will be more flush with fender).
• Minimum wheel bolt engagement inside hub is about 1 1/2 times the bolt diameter i.e. 14mm diameter
bolt will require at least 21mm engagement inside hub (or another way, 21mm outside inner edge of
wheel).
Currently Fitted
Mandus Manheim Painted/Gun Metal
Front! ! 8.5" x 19" ! ET 25 mm! 255/35 R 19! ! SKU: W-1985MAH255112B66

DIY Maintenance, Part Cross-References & Modifications
What Can Go Wrong? - General Problem Areas and Common Faults
The SL55 is fairly reliable, but... when it goes down it goes down hard.
The things that are weak on the car and will break (at around 100,000 km) are (in no particular order) :
• front ABC strut/shocks $1,200 ea - ($1,500 - $2,000 ea dealer installed)
• rear ABC strut/shocks $1,000 ea - ($1,300 - $1,700 ea dealer installed)
• ABC valve blocks $1,100 ea - ($2,700 each including installation)
• ABC tandem pump - power steering pump and ABC pump combined $1,200 - ($3,500 dealer installed). As
a space-saving measure the tandem pump was engineered as one unit.
• Intercooler pump ($500 dealer installed)
• Engine mounts ($2,500 for all three, dealer installed)

• Lower ball joints ($700 dealer installed)
• Supercharger bearing
An independent may be cheaper, except for ABC work (as components and fluid are expensive).
Brakes
This vehicle has sensotronic brake control (SBC). If the SBC light on the dash illuminates, have the brakes
checked. If the SBC is not working, limited brake pressure is delivered to the front brakes, increasing the
distance it takes to stop. The SBC hydraulic unit has a specific service life programmed into the control module;
follow the manufacturer's recommended service procedure for proper maintenance of the SBC. Follow the twoyear
service interval for brake fluid flush.
Engine
Oil leaks from the PCV vent housings on the valve covers and inspection plates on the front of the engine are
common. The rubber bond in the harmonic balancer can decay, which causes the balancer to move and work its
way into the timing chain cover. If the balancer comes into contact with the timing cover while the engine is
running, it will fracture and damage the timing case and potentially other surrounding parts. The harmonic
balancer should be inspected at every service. Oil leaks from the oil level sensor are common. The crankshaft
position sensors tend to fail.
Suspension & Steering
Front thrust arm and control arm bushings can crack and sometimes tear completely. If this is not repaired
quickly, damage to the front subframe unit will occur, which is very expensive to repair. Updated control arms
(that prevent damage to the subframe when the bushings wear out) are available. The active body control
system can leak fluid from numerous areas, including the tandem pump, hydraulic lines, struts, and/or seals. If it
is not repaired, the vehicle ride height could drop too low and cause damage to the undercarriage.
Drive Train
A vibration felt through the centre floor of the vehicle can be caused by driveshaft flex discs, which crack and
shred, causing excessive driveshaft movement. Not repairing these can cause damage to the driveshaft centre
support bearing, or, in the worst case scenario, damage to the transmission or differential. High mileage or older
vehicles develop leaks at the differential seals and cover; the whole unit needs to be resealed to repair the leaks.
The wire connector on the transmission leaks fluid into the wiring harness. If not repaired, the oil will migrate
through the wiring harness and damage the transmission control module. A new harness and control module are
required to fix the problem.
Electrical & Lights
Brake light switch failure can cause the ESP and BAS warnings to illuminate. The early versions of the central
gateway module (which allows different systems to communicate with each other) have software problems.
Heating & Air Conditioning
The evaporator temperature sensor can fail, causing the AC compressor not to cycle. If the AC compressor does
not cycle on, the AC system will not blow cold air. If the AC compressor is stuck on, the air will be very cold at
first, before warming up.
Repository of R230 Info
R230FuseMap.PDF
Vario Roof Diagnostic Aid.pdf
Manually Closing the Vario Roof.pdf
Dual Battery.pdf
FSS operating instructions.pdf

FSS reset.pdf
Instrument Cluster.pdf
Wiring diagrams - reading.pdf
remove shifter lever[1].pdf
remove center console cover[1].pdf
change front pads.pdf
change rear pads.pdf
The brake thread to go along with the brake pdf's.
http://www.benzworld.org/forums/r230...83-brakes.html
2004 SL500 MANUAL R230 SBC Tool info.pdf
2004 SL500 MANUAL R230 SBC Safety Sheet Involves BRAKES.pdf
2004 SL500 MANUAL R230 SBC Disable wo STAR_DIAGNOSIS.pdf
2004 SL500 MANUAL R230 SBC disable on other MB.pdf
2004 SL500 MANUAL R230 SBC ABS info.pdf
removal front bumper.pdf
removal rear bumper.pdf
replace fuel filter.pdf
headlight removal.pdf
headlight replace.pdf
Remove rocker panels, aprons, etc.
http___127.0.0.1_38562_repairandmaintenance_AZ_AZ88.pdf
http___127.0.0.1_38562_repairandmaintenance_AR_AR88.80-P-6000R.pdf
Steering wheel/Airbag
AR46.pdf
AR46.10-P-0100I.pdf
AR46.10-P-0200I.pdf
AR46.10-P-0300I.pdf
AR54.25-P-2802I.pdf

AR91.60-P-0660R.pdf
Servicing & Intervals
For all, their performance and luxury, the new SL55 is designed to be remarkably easy to live with, offering
flexible service intervals, dependant on way you drive car.
A full service history is absolutely essential, and itʼs equally important that the car has been looked after by a
qualified specialist. Gaps in the history should sound warning bells, particularly if they occur at the same time as
a change in ownership, and make sure bills for parts match the recommended schedule – itʼs easy to fill the
service book with oil changes but never do the more expensive maintenance jobs.
Service Parts
Servicing Costs (Labour + Parts)
• Prices vary significantly; these are rough estimates for costs at an independent shop.
• Minor service (every ?): c$?
• Major service (every ? miles): c$?
• Clutch replacement: c$0
• Brakes (pads plus rotor resurfacing): c$?-?
Parts Costs
• Front brake pads - c$?
• Rear brake pads - c$?
• New alternator - c$?
• New starter motor - c$?
• Replacement headlamp - c$?
• New exhaust - c$? (including catalysts but excluding manifolds)
Recalls
Jacking Points
For a floor/trolley jack, the 4 lift points are :
• front - protruding pins behind front wheels
• rear - protruding pins in front of rear wheels

A Service
B Service

Additional Work
Diagnostics and OBD II Scan Tool
OBD II Technical History

Since the late '70's early '80's vehicles have been equipped with sophisticated electronics to control vehicle
emissions and performance. Through the years several systems have been used, and keeping up with the
differences from year to year was a real chore, to say the least. Multiple scanners that attached to the vehicles
on-board computer systems were needed, and it was not uncommon for the scanner to become obsolete from
model year to model year. These were the days of the "pre-OBD I "(On-Board Diagnosis-First design) systems.
Beginning in '88 CARB (California's Air Resources Board) and the EPA (Environmental Protection Agency)
required vehicle manufactures to include a "self diagnostic" program capable of identifying an emission related
fault in the On-Board Computer systems. The first generation of On-Board Diagnostics came to be known as
OBD I. The CARB conducted studies on the OBD I vehicles and found that the system was not capable of
detecting an emission related component unless it had failed. The components that had not failed completely
were unable to set a DTC. Also, it was found that some systems not being monitored had failed and yet the
vehicle would pass an Emissions Test as the failed part would not be a factor unless the vehicle was being
driven or under a load. The CARB and the EPA passed new laws that would address the problems found during
the OBD I case study. These new laws and requirements are known as OBD II. Since mid-'94-'95 some vehicles
were equipped with the second design, OBD II systems. In '94-'95 only select models were equipped with this
new system, and in '96 every vehicle sold in the United States were equipped with the OBD II system. You might
be asking, ok, so what? Well, this was the single and largest improvement made to diagnosis and repair of the
On-Board Computer systems since their introduction. The DLC (Data Link Connector) that a scanner attaches
to, is virtually the same for every vehicle, and the "Generic" DTC's (Diagnostic Trouble Code) are the same for
every vehicle. The terminology was changed to terms that would be used by all manufactures. Before this, the
computer (PCM), for example, could have been called a Processor, ECU, Control Module, ECM, etc. To know
what the name of a part on a specific system was called or how it functioned, or was located, was tough when
you worked on multiple vehicle models.
Do you remember the early home computers? The box that connected to your TV set and allowed you to play
games and do light bookkeeping? Then the 286, 386, 486 computers each being a little faster and better than
there predecessor? Look at the OBD II system on your vehicle the same way, faster and "smarter" than any
other system used in computer equipped vehicles. This is good news for everyone. The vehicles perform better
(fuel economy, performance, longevity) and the "self-diagnostics" are simply amazing. If 20 years ago someone
would have told me that the on-board computer would be able to tell me that the fuel cap was loose or that a
specific cylinder was misfiring I would have laughed.
Does my vehicle have OBD II?
To determine if your vehicle is equipped with the OBD II system is fairly simple. The DLC (Data Link Connector)
must be located within three feet of the driver and must not require any tools to be revealed. Look under the
dash and behind ashtrays. All cars and light trucks manufactured since late 1995 should be OBD2 compliant.
Two factors will show if your vehicle is definitely OBD2 equipped :
• There will be a note on a sticker or nameplate under the hood: "OBD2 compliant”
•
•! There will be an OBD2 connector as shown below

Pin 2 - J1850 Bus
Pin 4 - Chassis Ground
Pin 5 - Signal Ground
Pin 6 - CAN High (J-2284)
Pin 7 - ISO 9141-2 K Line
Pin 10 - J1850 Bus
Pin 14 - CAN Low (J-2284)
Pin 15 - ISO 9141-2 L Line
Pin 16 - Battery Power
SL55 OBD II Access DLC Connector
How do I know the OBD II is functioning correctly?
When a problem within the system that will effect the vehicle's emission output is noted, the MIL (Check Engine)
will illuminate to alert the driver that a problem exists within the system. Also, the system will set a DTC
(Diagnostic Trouble Code) that can be retrieved using an OBD II Scanner or Code Reader. The DTC will lead to
the direction in which the fault occurred. This is one area that is misunderstood. The DTC is a "helpful tool" that
will be key in determining what happened within the system. One thing to keep in mind, the DTC is a STARTING
point in most cases. For example, a PO301 would be a misfire was detected on #1 cylinder. The first thing that
comes to mind is the spark plug, and there is a good chance the spark plug could be failing, but, a defective fuel
injector, spark plug wire or COP (Coil Over Plug) unit is failing and cause the DTC to set. Then all of the other
possibilities, basically everything that would have to do with the cylinder performing is a possible reason for the
DTC to set.
What is the difference in a Generic and Enhanced DTC
Every OBD II vehicle has to comply to strict emission standards. When the vehicle is new, this is easily achieved,
but what about after 50,000 or even 100,000 miles? Every OBD II vehicle is required to able to determine if a
fault within the system that would cause excessive emissions to be expelled from the tailpipe in the form of a
DTC.
The Generic DTC's are a list of mandatory trouble codes that must be present and able to be displayed should a
fault arise. There are many Generic DTC's and not all of them will be used on every vehicle. The ones used
depends on the yr/make/model/engine of the vehicle. The Generic DTC's are also designed to be able to be
retrieved using a standard OBD II Scanner or code reader.

The Enhanced DTC's are DTC's that are vehicle specific. Simply put these are DTC's that have been added by
the manufacture to further "Enhance" the diagnosis capabilities of the vehicle. Without this option every vehicle
would be a clone to one another. A simple example of an Enhanced DTC would be:
Ford Vehicles.
!P1227
! ! Waste-gate Failed Closed
Keep in mind that if your vehicle is '96 and newer, Federal Law requires that ALL vehicles (cars and light trucks)
sold in the United States MUST BE OBD II Compliant. This includes ALL Domestic, Asian and European
vehicles.
How To Test OBD II On-Board Diagnostic Systems
On-board diagnostic systems are more sophisticated than ever. OBD2, a new standard introduced in the
mid-'90s, provides almost complete engine control while also monitoring chassis, body and accessory devices.
Computers may seem more complicated than oil and grease, but The Part Pros are here to help you test your
system and locate any problems in the diagnostic network.
Since all vehicles are not the same please refer to the manual supplied with the OBD2 code reader for vehicle
specific instructions.
Important info about OBD II
! •! Can diagnose/check engine problems in all CAN and OBD2 vehicles (1996 and newer) and many of the
most popular OBD1 (1981 to 1995) vehicles
! •! Features unique patented all-in-one screen display and LED display for quick emissions check
! •! Automatic refresh updates data every 30 seconds when connected to the vehicle - an easy way to verify
repair completion
! •! Code definition can be displayed in English, French and Spanish
! •! Can be Flash updated with a standard Windows® PC
! •! Features memory/battery backup for off-car review and analysis
Connecting
Connecting the OBD2 Code Reader is as simple as locating the DLC connector.
Reading the LCD Display
Before you start testing, take a good look at the LCD display. The illustration above explains what the various
icons mean and how the DTC (Diagnostic Trouble Code) will be displayed. The unit is self-powered by three-
AAA batteries and will let you know when they are running low. When connected/receiving power from the
vehicle, the CAR Icon will display.
The OB2 code reader is a very simple tool to use. Once it is connected, turn the power on. Once the ignition is
switched to the on position, the code reader is checking the system for any stored DTCs.
The meaning of each DTC can be found in the manual supplied with your code reader.
Example: ! the code reader displays a DTC PO309, Cylinder 9 misfire was detected.
Once you know what the problem is, you have to determine what's causing it. In this case the intake manifold
gasket was faulty. Once the repairs have been made, it is time to clear the DTC and check the system to verify
the repair.
Clearing the Diagnostic Trouble Code (DTC)
Clearing the DTC is very simple. Press the ERASE button on the code reader. A message will display on the
screen; "SURE" for conformation. If you wish to clear the DTC press and hold down the ERASE button again
until a message appears on the screen "DONE". If you did not wish to clear the codes and hit Erase by mistake
at the screen message "SURE" simply press the link button to return without erasing any DTCs.

When you clear the DTC(s) from the PCM (Power train Control Module)you also clear ALL of the other gathered
information that the PCM has collected, including Freeze Frame, Drive Cycle data, manufacture specific
enhanced data end everything stored in memory is erased - just like if you cleared the Cache files on your PC.
The vehicle's PCM will need to re-learn the information that was erased. Don't be alarmed!! This is easily
accomplished just by driving the vehicle. All you have to do is get driving.
My Equus Innova 3030e Scan Tool
Note : Saves a lot of money, as over $150, each time the dealer checks for codes.
Engine - DIY Advice and Part Sources
Engine Oil Temps.
210 º F - normal street use?
230 º F - track use?
260 º F - heart attack range?
Engine Oil Pressure
10 psi for every 1000 rpm?
Warm - Max - 92 psi ?
Min - 64 psi?
Air/Intake Manifold Leak
Air/manifold intake leak: causing rough idling.

Oil Filter Element
• Mercedes-Benz ?
• AC Delco ?
• Bosch ?
Engine Oil
• Mobil 10w-40w Synthetic
• Royal Purple 10W40 Fully Synthetic (? US Gal ?US qt (? litres?)
Royal Purple Synthetic
Royal Purple Motor Oil Combines premium base oils with proprietary additive technologies to create high
performance motor oils that optimise engine performance and provide superior protection. No special
procedures are necessary when upgrading to Royal Purple. Royal Purple motor oil is fully compatible with
mineral or other synthetic oils.
Royal Purpleʼs API licensed motor oil delivers superior protection and improves performance in gasoline and
diesel engines. Royal Purpleʼs API SN licensed motor oil meets ILSAC GF-5 and Dexos11 performance
requirements. For those seeking enhanced performance in vehicles not under warranty, we recommend our HPS
Series of high performance motor oils with our proprietary Synerlec additive technology. Royal Purple motor oil is
compatible with other mineral and synthetic motor oils. Itʼs available in the following weights :
• 0W-20
• 0W-40
• 5W-20
• 5W-30
• 5W-40
• 10W-30
• 10W-40
• 15W-40
• 20W-50

SL55 Oil and Filter Change Procedure
Parts needed :
• ? litres of 10W-40 Oil
•
•
An DIY oil change is easy, but removing the engine cover/splash guard, while on stands, is a chore (investigate if
possible to reach oil filter without removing belly pan?) :
• Drive car on to
•
An alternative method to remove old engine oil
Use suction pump (like this “Topsider”) to extract oil through dipstick tube (most car dealerships do it this way
including Mercedes-Benz), and it has been tested to prove that you can actually remove more oil by this method,
than by draining. It also saves having it on ramps, etc., and possibly not level when draining, and also saves
much time having to remove and refit so many bolts for the under pans.
It may be possible to permanently remove a small portion of the engine cover/splash guard to enable access to
the oil filter and doesnʼt need access to the oil drain. An aluminium panel could be screwed in place which would
be much easier to remove.
Engine Oil Leaks
Take a close look for oil seepage from the timing chain cover, etc. If you require to replace any gaskets, take
the extra precaution of coating the gasket and bolts with a thin layer of "Magic Lube".

APPLICATIONS: For Motors, O-Rings, Gaskets, Bearings and Water Filters.
Magic Lube is a Teflon based non-melting, non-toxic formula that is waterproof for use in both wet and dry
environments. A wide temperature range, of 0 Degrees F to 425 Degrees F, makes Magic Lube ideal for use
under the most adverse conditions.
It forms a durable adhesive film of lubricant that prevents metal to metal contact even under severe shock loads.
Magic Lube is a superior lubricant compatible for use with most Metals, Rubbers, and Plastics. Magic Lube has
been USDA. H-1 Rated to be environmentally safe and corrosion free.
SL55 Spark Plugs (16)
The book recommends new spark plugs every 40K miles, so you should wait until that mileage is reached,
irrespective of timeline. It is recommended to replace with NGK Iridium plugs and you should never have to
replace them again .
Old Plugs - Condition Chart (circle each plug number as you remove them)
Dry/OK?
1___2___3___4___5___6___7___8 ! 1___2___3___4___5___6___7___8
Burnt?
1___2___3___4___5___6___7___8 ! 1___2___3___4___5___6___7___8
Oiled?
1___2___3___4___5___6___7___8! ! 1___2___3___4___5___6___7___8
Sooty?
1___2___3___4___5___6___7___8! ! 1___2___3___4___5___6___7___8
• MB ?
• NGK ? Laser Platinum
• NGK ? Iridium (cannot currently locate an Iridium match)
• Gap-?” (? mm)
• Thread-?mm
• Hex Size-?ʼʼ ?” ?mm
• Reach-?” ?” ?mm
• Torque -
NOTE : 6 = Heat range (6 is almost smack in the middle of the full range of plugs, 1 = hot, 12 = cold)
Why Iridium?

• Enhanced spark precision, thanks to the 0.4mm Iridium centre electrode
• Iridium is six times harder than Platinum
• Iridium is eight time stronger than Platinum
• Longer life - has a melting point 1,200 degrees higher than Platinum, and twice that of pure Gold
• Iridium plugs perform at peak efficiency longer than any other plug design on the market today
• Better spark - U-Groove ground electrode technology produces a more efficient flame combustion and
maintains a quality spark even at low voltage levels
• Tested power increase by 1.4% along with a 5% improvement in fuel consumption
Spark plug Installation (needs updated) :
• Not really difficult to do, but you have to take the air boxes out along with the upper intake.
• Remove each coil pack by removing the two bolts/washers on each, then using special coil pack remover
tool (see below).
• Swap old spark plug for new, and tighten (do not over tighten). Tighten by hand and then torque to 10Nm
or no more than 1/8th of a turn.
• Do not forget to put anti-seize compound on the spark plug threads.
• Refitting the coil-pack tighten to 10Nm (do one at a time so there's no chance of getting a coil in the wrong
cylinder).
Air Filters (2)
Air filters are clearly essential for engine life. Properly fitted they will improve power by ensuring a good supply of
clean, cold air. There is a lot of hype about filters improving power. Some certainly do but only when they
improve upon the existing set up. Fitting a cone type filter such as a K and N 57i or BMC VAS may well improve
flow, and possibly throttle response but if the filter then draws hot air from the engine it will not improve power. In
fact it could well reduce power. The same applies for air box drilling.
We have read of lot of information on filters over the years. We personally feel cotton gauze are the best ONCE
they have had time to develop a layer of dirt to increase filtration efficiency. In terms of flow we feel they are
superior. However in terms of dirt filtration we were surprised to read the results of this test which showed that
foam were much better in multilayer style than cotton gauze for filtration efficiency alone.
http://www.ducatigarage.netfirms.com/filtertest.html - to read the full test
IN BRIEF from an airflow perspective
Bronze Medal
As you would expect, the paper element finished third It captured around 120 grams of dirt over an 11 minute run
before the filter became clogged and registered the pressure differential drop on a manometer of 6 inches of
water.
The starting reading was 17.84 inches of water, and the ending differential was 23.84 inches of water.
Silver Medal
The RamAir (similar to Pipercross) multi-stage foam filter finished first in dirt holding holding capacity. It captured
a massive 199.81 grams of dirt but with a larger starting and ending pressure differential. This means the foam
filter works well out the box but less well with a layer of dirt.
Gold Medal
The K&N cotton gauze filter (BMC air filters and Green also use cotton gauze) finished second in terms of filter
efficiency with it capturing 140.08 grams of dirt over a 22.8 minute run before the filter clogged up and registered
the pressure differential change of 6 inches of water. HOWEVER the start pressure drop was just 16.8 inches of
water making this the all round filter. The starting differential pressure was 16.80 inches of water and the ending
pressure differential was 22.80 inches of water.
BMC Filters including the Carbon Dynamic Air box. This device ensures a supply of cold air to the filter and using
a venturi effect and front air intake actually increases the velocity and volume of air being drawn into the engine.

If the air box is not listed for your vehicle we can either custom design and install a setup for you or if you are too
far away you can order a range of pipes and clamps that should enable you to install a CDA on any vehicle. We
still offer cone filters from BMC, K&N and Green but remember with these to focus on getting a good cold air
feed.
In addition have a look at our Heat Management products. If you can reduce under bonnet temperatures then
you can probably increase power.
• OEM
• Green Air Filter - Part # 2247 (2 required) + 15 hp. Constructed with 100% polyurethane on all four sides,
this high flow, oiled OE replacement performance filter will out flow stock paper filter for improved
horsepower and torque. Five layers of progressively finer mesh cotton gauze media provide maximum
airflow for best performance results. Washable and reusable for multiple cleaning cycles, the tall open
evenly space pleats provide excellent dust holding capacity for longer service cycle between cleanings.
Integrated urethane bump seal insures tight, no leak seal over the life of the filter.
•
Cleaning the Throttle Valve
Note : images below, show procedure on an Aston Martin V8 Vantage engine, but procedure is similar for other
cars with throttle valves.
The throttle valve, over a period of time, can build up a sticky oily residue. This can cause issues with low rev
throttle response, but easily rectified and only takes about 10 minutes. You need a medium-sized flat-bladed
screwdriver, and carburettor/injector cleaner aerosol.
• Pull the black pipe off, so that you can see the throttle flap.

• Wearing goggles, and using carburettor/injector cleaner aerosol, spray the metal flap, also opening the
flap with your fingers, so that the edges and intake area is properly cleaned. The excess cleaner will just
evaporate away, and as this is flammable the usual precautions should be followed.
• Now, just refit the pipe and clip, making sure it is fastened correctly.
MAF Basic Test
Before replacing your mass flow sensor, you can do a basic test.
Cleaning the MAF (Mass Air Flow) Sensor
If a check engine light comes on and you find a P0101 code with your scan tool, that means a problem with your
MAF (Mass Air Flow) sensor. The car will probably be stumbling when you hit the gas. A quick test, with the MAF,
if your finding the power from engine is down, just unplug the MAF (if engine comes back to full power, then it is
the MAF).
Easy to replace (takes less than 5min) :
• Pull the front air box cover up, and then towards you.
• Pull off the 2 plastic air tubes.
• Lift the whole air box up and off.
• The MAF is the plastic housing that the air gets forced in from the air box.
• Disconnect the wiring harness
• Unclip the plastic holder and pry the holding clip back with a flat screwdriver.
• Install in reverse.
MAF around $168 from Auto Parts at AutohausAZ - OEM Auto Parts. I was quoted over $1000 for the dealership
to replace it. Cheapest place should be Bosch, as they made it.
Changing Fuel Filter
On
Oxygen Sensors

The O² sensors are made by BOSH, so its very easy to find them on the internet, for around $81 front and $177
rear each, yet the dealer quotes $1,488 for all 4, parts only, and not installed.
The O² sensors are installed in treaded holes in the catalytic converters, and are pretty easy to change (but a
little bit fiddly to access). For the fronts, you just have to remove the bottom covers, then use a bent 22mm
wrench and pull/replace a connector.
Cooling System
? US Gal - Mix of water and coolant with anti-freeze (CUNA NC 956-16 Shell Glycoshell) (Specification -25
degrees C).
Antifreeze if it is blue is Texaco. You can find it if you shop around. Sometimes at Advance Auto Parts. If it is
green you have no idea most times but you can use the Prestone universal for now.
Best bet is to make sure the fluid is kept fresh ever year. If you are going to do it yourself. Make sure the shop
doing the belt service drains the entire system when the belts are done. Some guys don't drain the system at the
dealership so keep that in mind. The level is in the owners manual.
Upper Coolant Hose
When car cold the upper radiator hose is collapsed, but when you loosen the overflow tank cap it "inflates"
again.
Abnormal. When hot the pressure builds up in the cooling system and this lifts the spring on the expansion tank
cap. The pressure exits via the small pipe by the cap. When it cools the pressure drops and a vacuum is formed
which draws air back in (or coolant if there is an overflow bottle attached). Possible faults :
• Check the overflow pipe for blockage from the tank to the outlet
• It could also be a faulty tank cap
• Or the top hose has lost its resistance and become weak (if hose is easily squashed and feels soft,
replace it)
Cooling Fan
The cooling fan in the engine doesnʼt work at 100%, normally happens to the 95-98, minor problem but I think
the age has something to do with it.
Over-Heating or Low Coolant Warning Light
Engine Water Temperature should run right on 90 degrees.
There may be a number of issues here. The first relates to bubbles in the coolant system and the second to a
drop in coolant level due to heat expansion in the flexible joints of the plumbing. For the first, try Porsche Pete's
Boxster Board for a procedure to "burp" your system. For the second, there may or may not be an official fix -
check your dealer and PNA. However, Porsche did something and it seems that cars from April 99 on, and
maybe earlier, have the fix. Another possibility may be that under very hard acceleration coolant is actually
temporarily sucked out of the reservoir to the point where the warning is displayed. Topping off the car and
restarting may clear the light.
I have recently heard that one of the PAG factory machines had a fault up until April 99 that may have resulted in
sub-standard casings and the resulting overheating problem. This is entirely unsubstantiated at present but if
true would mean that cars built before April 99 will not all suffer from this problem. This has certainly been borne
out by my own experience and that of others who have older cars but who have never experienced this
unfortunate ailment.
Changing the ratio of coolant to water and adding Redline Water Wetter, may also be a fix. Reducing coolant
and increasing water will cool better (water cools more efficiently than coolant) but this probably puts your
radiator at more risk from oxidation. Different folks assess this risk differently and I do not feel qualified to give an

opinion on it. However, this possible fix is certainly cheaper, if it indeed works, than some alternatives (oil
coolers, additional radiators, etc).
Exhaust System

Muffler Delete (new tips)
Rear mufflers can wear out/corrode/etc. and are very expensive to replace (more than $2,000 each). A cheaper
replacement option is to have a muffler fabrication shop replace with dual tip Magnaflow mufflers.
• The magnaflow tips are staggered (outside is shorter)
• The tips are inside bevelled
• They are super quiet and do not drone on highway

Catalytic Converters
Catalytic converters are quite expensive items for any car, they need checking as a car with either poor cats or
cats removed will fail an MOT, however we have also had reports on cars that run without the cats fitted may not
be insured as they are not road legal, for the potential 5bhp of extra breathing capacity - its just not worth it.

Transmission
? US Gal (? litres) Shell M1375.4 DEXTRON III
Checking the Gearbox Oil
•! Detach
Changing the Gearbox Oil
Transmission Service (Fluid and Filter)
Air Conditioning - DIY Advice and Part Sources
System requires regular recharging
System Coolant ! 0.29 US Gal (1,100cc)! ! R134a
Compressor Oil!! 0.033 US Gal (125cc)! ! Type SP 10 (Sanden)!
A/C - Low and High Ports
High side service is located
A/C Drains
If some debris.
Trinary Switch
Trinary switches provide compressor protection against high side pressures that are too high or too low. There
are 2 styles of pressure switch, binary and trinary.
The binary switch simply splices between the compressor clutch and evaporator thermostat and taps into the
high pressure line. When pressures exceed safe limits, the switch opens the circuit to the compressor clutch thus
disengaging the compressor until pressure return to normal.
The trinary switch operates much the same as the binary in that it shuts down the compressor when pressures
rise. However, the trinary also controls an electric fan on the radiator that pulls additional air across the
condenser to bring pressures down.
us engaging the fan and an open circuit on the compressor connections which disengages the compressor).
Location
On the

Evaporator
Evaporator
348 (1989-1995) A/C Charging (as example)
I just recently performed the A/C service on my 1995 348, in doing so I discovered a product that works better
than traditional R134a. So I decided I would put together my first How to, for all of you do-it-yourselfers there on
FChat.
The product I used was called Arctic Freeze Refrigerant R-134a+ It is made by Interdynamics; it replaces lost
refrigerant & oil to the A/C system and was developed for NASA. If you would like to do some reading up on the
differences of R134a to R134a+, here is a link to a .pdf file that I used.
http://www.originenergy.com.au/business/files/r134at.pdf
I can attest to it being a much better product to give your Ferrariʼs A/C better cooling. A link to their website and
product page is below.
http://www.id-usa.com/product.asp?CID=7&PID=215
About R12 and R134
All 1993 and newer vehicles, are supposed to use Refrigerant #134a and 134a oil. R134 uses different oil than
the older R12 system, and since R134 doesnʼt get quite as cold, the R134 system typically uses more Freon.
Many manufacturers didnʼt want to redesign the A/C, so they continued to use the older systems, filling them
instead with R134, and retrofitting them with the newer style ports. Please be aware of the type of system you
have before beginning, an easy way to tell is looking at the Charge ports.
Charge port for an R12 system
Charge port for an R134 system
If you have charge port for R12, take it to a qualified service centre (either to be converted to R134 or charged
with R12, which is unavailable to the public). Note - the cost of replacing all the failed parts from mixing the 2
different types of refrigerant and oils will cost well into the thousands.

To refill a partially discharged system
You will need Freon, and the appropriate charge hose. These are available at your local auto parts store. Some
cans come with the hose, and a relatively useless gauge. The gauge is unreliable, and shouldnʼt be used to
guess the amount of Freon in the system, as itʼs only measuring pressure, and not the level of the Freon.
Pressure varies with the outside temperature, and the temperature of the parts, and the barometer outside the
car, making the gauge next to useless.
• Locate the dryer (on the 1995 Ferrari 348 the dryer is located on the passenger side of the trunk, under
the carpeting). It looks something like this:
•
• On the top of it is a little glass window (verify that your Ferrari has this window).
• If it does not, please take it to a service centre to be filled (they will carefully meter out the Freon and add
the exact amount).
• Start the engine, and turn the Air conditioner on full.
• Attach the can of Freon to the low pressure charge port.
• Look at the glass window on top of the dryer (there may be foam, or bubbles, or very slow bubbles
depending on the level of charge).
• Open the can of Freon very slowly until you feel the top of it get cold.
• As the system charges, the window will go from fast foam to slow foam to bubbles to slow bubbles to
“clear”.
• Once it reaches “clear”, the system is charged.
• Fill it slowly, as itʼs easy to overcharge if youʼre in a rush (just barely crack the can until it starts to get cold
and watch the window carefully).
• After all the bubbling / foaming stops the system is full.
• Shut off the can.
• Run the system for an additional 10 minutes (if any bubbles crop up, add a tiny amount of Freon until they
are gone).
If the system is fully discharged:
• First you must vacuum out the system to remove any moisture.
• If the system has been wide open for some time (like if you had disconnected the A/C lines and left it that
way) then it is recommended for maximum performance, that you replace the dryer/accumulator. If you
donʼt I advise you spend additional time vacuuming out the system.
• Vacuuming out the system requires an A/C vacuum pump, and also the R134 Charge hose. Both should
be available at a local auto parts supplier.
• You should vacuum out the system for at least 5 minutes (longer if the system has been open for any
period of time).
• Verify the system is holding a vacuum (this can be done using an A/C pressure gauge). If the system still
had Freon in it before you began, itʼs generally safe to assume that there was no large leak, and that the
system is still holding vacuum.
• Check the service manual, before charging the system, to verify the capacity of the air conditioning system
(do not overcharge the system). Most R134 systems will take somewhere in the range of 18-24 oz. of
Freon. To gauge the amount of Freon, first look at the capacity of the cans (most of them are 12oz).
• If you have replaced the Compressor, or otherwise had the system cleaned with A/C solvents you must
add the amount of compressor oil specified in the service manual.
• If you have not replaced anything, you should add 2-3 oz of R134 compatible oil (add the oil first, before
adding Freon).

Body - DIY Advice and Part Sources
Rust Prevention
When youʼve got a mint-condition 360, but you want to use it as your everyday car and cover about 10,000 miles
a year in it, youʼve got to work out how youʼre going to do that and still keep it looking good. You can lovingly
wash and wax it, but what about whatʼs going on underneath the car, and how do you keep the dreaded rust at
bay?
The best way of protecting the car against the inevitable assault from water and, even worse, the tons of salt that
councils will no doubt be throwing down once the big freeze begins, is a full cavity wax injection with a full under
seal.
• First it is power-washed and then fully steam-cleaned underneath
• The car is then thoroughly fan-dried
• Next the treatment is carried out
• Any areas of surface rust are carefully treated with a rust cure
• Then every single cavity is injected with Dinitrol 3125 (all the doors, the sills, the wings, the rear side
panels, the bonnet, the chassis members. . . the lot)
• Then the underside is sprayed with the 3125, followed by a coating of Dinitrol 4941 (a glossy black under
seal that never dries hard but maintains a waxy feel to it)
• The car is then allowed to dry before collection (so takes about 3 days)
• Total cost around $1,000, but should last five years (cheaper than replacing a wing/fender or sill)
Note : the combination treatment of Dinitrol 3125 with Dinitrol 4941 is considered more effective than Waxoyl.
Rust Inhibitor (POR-15)
Injecting something, even a good phosphate conversion etchant, is like prescribing sex to a nymphomaniac; at
best it's temporary relief. Also, most etchants need to be neutralised, usually by a thorough water rinse,
otherwise the phosphoric acid will cause rust to resume more aggressively.
You need to kill the rust, which the POR15 metal ready etch does, by converting it to zinc phosphate. You then
seal it with a coating that's impervious to oxygen and moisture, which the POR15 paint does. Then it can be
repainted & won't resume, as the paint further seals the surface. Bondo doesn't work because it doesn't block
moisture. However, you can use bondo over something like POR15, then the paint will seal the bondo well
enough so that problems won't develop.
Sandblast or grind out the rust affected areas, apply POR-15 followed with 2 coats of rubberised undercoating.
POR-15 dries rock hard. POR-15 flat black paint can be used as the top coat.
Rust Inhibitor (LPS-3)
Spray LPS-3 rust inhibitor spray on the inside of the door and look for a couple of used, galvanised doors.
Underbody Protection (Wurth SKS Stoneguard)
Without doubt, Wurth's water-based black undercoating. You can spray or brush it on. It goes on grey, then dries
to a PERFECT satin black match. Matches OEM Porsche, BMW, Mercedes and other European auto makers'
"body schutz" or undercoating.
Can be built up because it doesn't run on vertical surfaces. SKS is water based, fast drying and flexible when
dry. May be painted or left as applied. It is best applied with a Wurth SKS Gun, but may be applied with a brush.
11335 Wurth SKS Stone Guard - Beige, 1000 ml bottle
11336 Wurth SKS Stone Guard - Black, 1000 ml bottle
11337 Wurth SKS Stone Guard - Grey, 1000 ml bottle
11338 Wurth SKS Stone Guard Spray Gun
They now have the stuff in 14 oz spray cans (aerosol). Manufactured in Germany.

Mail order company : http://www.autogeek.net/w890971.html
This rust-proof coating is sprayed on in minutes, dries in just a few hours (two to three), and offers heavy duty
protection for years. Wurth Stone Guard Black protects the wheel wells, rocker panels and undercarriage of your
automobile from inevitable damage from stones, debris, salt water, and road chemicals that eat away at the
finish, paving the way for rust. Wurth Stone Guard Black, a rubber/plastic ultra-protective spray-on coating is
easy to apply, tough as nails, and can be painted over, so as to match the colour of the car. One or two thin
coats in your wheel wells and on the undercarriage provides permanent protection from originators of rust. The
handy spray can means no messy cleanup or applicator tools. The textured, hard but flexible material deflects all
manners of shrapnel that can abrade, nick and chip away at the under-surface of your car. Best of all, itʼs
waterproof, so rust doesnʼt stand a chance.
Tech notes
Be sure to use in a well ventilated area. Allow to cure naturally for two to three hours. You may layer coats until
you attain the desired texture. Remove overspray with Wurth Clean-Solve.
To use
For best results, thoroughly clean surface that will be treated of dirt, grease and grime. This ensures that Stone
Guard adheres properly. Mask surrounding areas. Spray surface in short, even strokes until the desired texture
or thickness is reached. Allow to dry completely and naturally (two to three hours).
Weatherstrip Maintenance (Cures squeaks, etc.)
Iʼve been looking into which products would be best for weatherstrip maintenance and have decided to avoid
silicone-containing products altogether. Through a series of e-mails and research, my personal choices are :
• 303 Aerospace Protectant (with UV screening) for routine use on all exposed rubber and other select
surfaces
• DuPont Krytox Lubricants for problem areas that squeak (rubber and plastic alike), such as the header rail
in convertibles, cup holders, etc.

Proper use of 303 Aerospace Protectant requires :
• the areas to be treated be clean of any dirt or oils
• then thoroughly wet the surface with Protectant and allow to soak for approximately five minutes (rubber)
before wiping dry with a soft, lint-free cloth
• reapplication is recommended “every 30 to 80 days of exposure” or when the water repellency begins to
diminish
This product is widely available at a reasonable price. Shelf life is a minimum of five years. Two sources are
Autopia Car Care and Autogeek.
Krytox Weatherstrip Lubricant may be applied after the 303 treatment, if necessary :
• treatment areas for Krytox should receive limited exposure to dust and dirt, as it may remain somewhat
tacky and can attract dust (it could also rub off on clothing if applied too heavily).
• unlike the 303 product, Krytox is not wiped off after application, rather a thin layer is massaged into the
rubber and left in place.
• available as both an oil and light grease, choice depends on area being treated and/or personal
preference.
• care must be taken not to get any on glass or painted surfaces, not because of potential damage but
because itʼs difficult to remove once itʼs on there.
• reapplication isnʼt necessary nearly as often as with 303 Aerospace Protectant.
• Shelf life is indefinite.
Distribution of Krytox, is rather limited and cost is quite high :
• GM sells a 1 oz. applicator bottle for between $69 and $88 US
• itʼs referenced in the “2007 Chevrolet Corvette Owner Manual” in the section entitled “Recommended
Fluids and Lubricants,” under “Weatherstrip Conditioning”: “GM Part No. U.S. 3634770, in Canada
10953518.”
• Also recommended is “Dielectric Silicone Grease (GM Part No. U.S. 12345579, in Canada 992887)”; more
about silicone in a moment.
• Chrysler dealerships sell the same one ounce bottle of Krytox Weatherstrip Lubricant (MOPAR Part No.
04773427) for about $85 US
• Volkswagen offering costs even more
• Ecklerʼs, where a small tube of “Krytox Weatherstrip Saver” grease (Item #A2524) sells for $44.99
• Jaguar endorsed use of Krytox fluid for interior squeaks ten years ago as outlined in Service Advisory
“910-01 APR 98.”
Wiper Blades (2)
• Part # ?
•
Vario Roof
Roof Squeak Fix (McLube Spray)
Here's my cure, from my wife's 09. The dealer lubed the roof after it developed a problem, but that was a shortterm
solution. Honestly I think that the detailers just got too aggressive.
The magic 'stuff' is McLube spray and McLube One Drop oil. They're available for the marine market, from
chandleries and various online sources. Magic. I've used it a lot on boats. I use both products.
1) Cover your seats - cheap insurance. Retract the top and open the hatch. If there is dust or dirt inside the roof
or the hatch sills, vacuum it out. Get the remainder with detailers spray and a rag.

2) Clean excess gunk from ALL bits of the track with a Q-tip. I didn't use cleaner or solvent. Wouldn't recommend
it. Look hard. Find every bit of the track you can, from the top, from inside. Retract the roof a small amount to get
to the aft track bits. Be sure to get in (as best you can) to the diffusers/seals both fore and aft of the glass. The
rear is especially tough, barely possible.
3) Do the same for all moving parts of the hatch hinges and the lock flange. There hinge mechanism is pretty
complex. Actually quite cool.
4) Use the McLube oil on a Q-tip, to coat the tracks (not the sills, the black track), the hatch hinges and the
flange. You don't need a lot of oil, just coat the surface. Excess just attracts dust. Again look hard at the track.
Find & lube every bit you can - from inside & out, partially & fully retracted roof.
5) Cycle the roof and the hatch. Repeat the lube process.
6) For the moving bits of the diffusers/seals you can't reach, use the McLube spray with the red tube extension.
Both diffuser pieces have hinges. I think that the rear diffuser/seal (between the roof and the hatch) is the source
of 90% of the problems. So look closely - anywhere that hard plastic sits against a solid piece of the roof.
The McLube spray dries clean. It will not attract dust and grime. Its possible that the McLube spray would do the
whole job. No need for the oil. I'd consider trying that if your car is in a dusty environment. But since Porsche
used a more viscous product, I use the bearing oil.
Total time? Maybe 20 minutes
Result? - Silence. No issues.
Oh and don't wear jeans. You'll be leaning over the car a lot, easy to scratch your paint.
Problem With Fuel Tanks Baffles
If you have a loose fuel tank baffle it can be fixed and will save you at least $4,000. All work is undertaken in the
boot (trunk) with the roof closed and took around 1 hour and is best done with as little fuel in the tank as
possible, my gauge showed a quarter tank. There are currently two fixes :
Fix 1 :
• Remove the boot separator (4 press studs, 1 either side and 2 on top and lastly 2 bolts where the hinges
attach to either side of the boot, these will be under small plastic covers which just unclip)
• Lift out the boot/trunk floor.
• Remove the carpet cover at the back of the boot (there are just 2 screw fixings under plastic covers near
it's base, it's not attached at the top just wedged in). This panel is overlapped by the boot side panels but
only by half an inch so can be bent a little either side and coxed out. If you're uncomfortable doing this,
you'll have to remove quite a lot of the boot linings to get the side pieces off, and really it's not worth it.
• Now you'll see the bulk head covering the fuel tank and the cut out at the top for the fuel gauge (you'll
soon be seeing the mythical baffle). The sender is slightly covered by a fixing strip that the boot separator
attaches to.
• Remove the plastic trim strip (again just 3 push clips)
• The sender is a bayonet fit in to the top of the tank and only needs a quarter turn to remove, but make
sure you unclip the sender wire first.
• Before removing, the sender, remember to make a mark on the tank and sender to help when refitting it as
it only works in one position.
• You may be able to simply remove the sender by jamming a couple of bolts into the holes and turning by
hand, if it has not been over-tightened. However, if too tight, the only easy way to remove the sender is to
fashion a makeshift “F-shaped” tool to locate in two holes in the top of the sender (use a 1/4” tube/bar
about 6” long, with 2 screws attached on one end approximately 2” apart).
• Also found that with a pair of "bent needle nose" pliers you can stick one tip in each hole of the fuel sender
and just twist. No need to buy or make a tool to turn the fuel sender unit.
• Once you have the sender out, you'll be able to see the baffle.
• A small torch/flashlight will let you see clearly.
• Poking a piece of bar inside the tank and prodding the baffle, will let you see what causes the banging and
why.

• The baffle runs east/west through the tank and is about 3/4 the height of the tank. It's fixed at the bottom
and should be fixed at either side (end). This is where the weld will have failed, allowing the baffle to hinge
front and back (acceleration and braking), knocking on the wall of the tank.
• There's no way to remove it without cutting the tank in half. It's about 36" wide by 12" tall.
• The baffle kinks about 45 degrees near it's top forward to the front of the car and it's this edge that hits the
wall of the tank.
• To fix, note there are a few slots cut along the top of the baffle where it kinks forward.
• Drill a 5mm hole in the top of the tank just above the sender (Many may not want to do this, so you'll need
to be very creative to work out another way)
• Take a regular coat hanger and just bent a hook at the end (I actually doubled up the wire by folding it in
two first for a bit of extra strength). You can work out lengths and angles by first pushing the wire through
the sender hole and locating one of the slots (there are 3 to choose from, and you have good access and
vision with the slots being practically level with the sender hole).
• Get the hook in one slot and out of the one next to it for a secure hold.
• Push the wire through the hole you drilled (the hole has to be above the sender to avoid fouling it when it
goes back in). A good idea is to use a piece of rod or anything you can push through the slot to pull the
baffle toward you slightly to give some tension to the wire hook, then all you need to do is bend off the
wire where it exits the hole (this is where doubling up the wire will work out well).
• Tape the wire in place.
• Use a little sealant in the hole to seal it fully.
• Replace the sender, check that it works and refit the boot/trunk parts.
Fix 2 :
• Getting to the sender portal is easy....10 minutes
• Take out the spare tyre stuff and carpet to bare metal
• Unscrew the two screws at bottoms sides of centre back carpeted panel
• Remove 1 silver screw on each side holding luggage cover in place
• Reach to front of luggage cover and unsnap about 6 snaps
• Remove luggage cover
• Pry loose and remove centre carpeted panel
• Sender unit is exposed
• Disconnect the two plugs.
• To open the portal you need to make a tool (find a 1" by 2" piece of wood and drill 2 screws through, so
they stick out at least 1" through the wood, about 2.5" apart to fit into the grey holes at 12 oʼclock and 6
oʼclock on the sender unit).
• Fit your new tool into the grey holes and rotate your tool like it is a wrench (counterclockwise from 12
oʼclock to about 10 oʼclock).
• Also found that with a pair of "bent needle nose" pliers you can stick one tip in each hole of the fuel sender
and just twist. No need to buy or make a tool to turn the fuel sender unit.
• The sender unit is now loose.
• Remove the sender unit....now you have your window through which to perform the operation.
• Getting the right spring in the right spot....that's a little harder.
• Look at the picture of the gas tank above, picturing a vertical divider wall running vertically, the length and
height of the tank about 3" from the drivers side of the tank (the spot welds at the top have failed and as
the gas sloshes, this divider wall knocks between the front wall the internal end of the gas filler).
• Just make sure you take every precaution to not drop anything in the tank (use some fine wire connected
to all, that can be cut and removed, once everything is hooked up).
• Using a heavy duty coat hanger (a metal garden tomato stake works well) to hook on and pull the baffle
away from the front wall of the tank (hooked over the baffle plate, where there is actually a handy slot in
the baffle plate, just below the bend).
• Drill a hole in the plastic of the sender unit, and hook the spring into this hole. Note, you must drill the
hole in the dark grey area near the top, so not to interfere with the operation of the float
mechanism.
• Spring selection is critical. A good spring size is about 6” to 8” (hooked on each end), of around 1”
diameter, and that is fairly stiff (to hold baffle steady), but allows you stretch it to about 9” (to clip over

affle). The material for spring shouldn't matter really, as the gas should preserve it and there is very little
air.
• Attach the spring to the sender unit and insert the whole sender unit assembly loosely into the tank.
• Alongside the sender unit and first coat hanger (pulling on loose baffle), insert a twistable rod LED light,
and a second coat hanger/forked tool (to hook the loose end of the spring over the baffle), maintaining
pulling pressure on the baffle with the first coat hanger.
• Work the second coat hanger/forked tool to hook the loose end of the spring over the far edge of the baffle
plate (will take a few tries to figure out how to manipulate everything through the small opening)
• It will take about 3 hours to disassemble, fix, and reassemble.
Fix 3 (similar to above, with improvement) :
The only item I did not like about your fix was the drilling part (rest of it was brilliant). I hate drilling anything on
the car.
• Removal was easy
• With the help of small led flash light (not torch) look inside and see the mysterious baffle
• You will notice a different anchor point for the spring, so you donʼt have to drill your tank (you can feel it
after you stick your finger inside the tank)
• You will notice there is rear baffle (which you wouldnʼt be able to anchor anything there using your
fingers), but for this job you will need L-shaped pliers
• Use the pliers to bend the wire into the desired shape (as shown on drawing), and 15 minutes later youʼll
have the trunk going back together
• Should cost about $300 for a mechanic to help (it sure beats $4000 bill from Mercedes dealer.)
• If you live in New York Area you can call them at 631 789 4085 ask for Sebastian.

Instruction How To Access Fuel Tank Sender and Repair Using Spring
Takes a little less than an hour and no more knocking sound.

Remove trunk partition and store safely

Remove two of the 2-piece fasteners from each side of the plastic piece on top of back carper panel.

Alternative Fuel Tank Repair
There is an alternative way to accomplish the same as the “spring method”. An MB tech (independent) removes
gas tank and sends to a local gas tank repair shop that knows how to repair. Basically :
• they drill a hole in the tank just below the sender (very small hole the diameter of a piece of coat hanger
wire for example)
• they push a piece of coat hanger (for example) through this small hole
• then remove the sender so they can reach in with pliers and put a hook on the end of the coat hanger (to
hook on the baffle)
• they then push in the coat hanger "hook" and hook the baffle with it
• then they pull on the hanger hard, bend it at a 90deg angle, and weld the junction between the hole and
coat hanger, to hold it in place (if the coat hanger is a tight fit in the hole, you could probably use silicone
or better, JB Weld, to seal any very minor gap, and then just duct tape down the piece of hanger along the
outside of the gas tank so it doesn't move around too much).
Another Simple Alternative Solution
• take a broomstick (donʼt even have to remove the broom from the end)
• stick it into the tank, through the fuel sender hole
• note in the pics of the tank, the baffle has a bend in it (where the "pulling tool" is inserted as described
earlier)
• rather than hooking a pulling tool there, so you can get a spring higher up on the baffle top edge, bang as
hard as you can on that pulling-tool area and you'll flatten the baffle
• remember the baffle has a huge bend in it where the pulling tool is inserted, so if you hit it hard a couple of
times, it flattens out the baffle (or maybe even bends it the other way a bit).
• for good measure, hit the baffle along that fold line/crease about 6" to the left, and approximately 6" to the
right also (just hit it in a couple of spots so you flatten it)
• now the baffle is "larger" because itʼs flattened, and it doesn't make a noise at all, as itʼs wedged in the
tank and doesn't move.

• the fuel gauge will still work as the baffle will now be farther away from the sender than when it was and
there will be no noises.
Yet Another Fuel Baffle Repair Method
Here is another alternative method using the exact step by step removal photos (above), but this an unbelievably
easy fix without using any metal springs, etc.
You will need :
• a length of very strong thin webbing, similar to the strap material used to secure the loads on the back of
lorries/trucks, but a thinner version (easy to buy from various DIY shops, etc.)
• a single length of rigid pliable copper sheathed cable (simply strip out a neutral cable from a roll of
everyday twin and earth mains cable)
• LED torch/flashlight (do not use a normal bulb torch for obvious reasons)
• a three pronged grabber will help enormously
At the end of the fix, the webbing is the material to do two things :
• bends the baffle back and away from the wall and
• is tied off to hold the baffle away from the wall.
Procedure :
• obviously the tank has to be virtually empty (its the fumes that can spark)
• tape one end of the webbing to one end of the sheathed cable
• make a long U bend in the other end of the copper cable and fish the cable into the fuel sender hole and
hook in and around the top of one of the slots in the top of the fuel baffle (you will see using the led torch)
• Using a three-pronged grabber to grab the end of the copper cable, once hooked around the baffle slot
and drag the cable back out of the sender (it takes a while and you need patience)
• then pull the cable until you have both ends of the webbing (the baffle is now in your control with the
webbing)
• then gently pull the webbing until you are happy the baffle is bent back enough, but mindful that there may
be other welds on the bottom of the baffle that may break.
• the trick is then fishing the webbing up and around the horizontal bar (that you will be able to feel when
you put you fingers into and up inside the fuel sender hole)
• now simply knot the webbing
• close the fuel sender
• Reassemble boot/trunk, etc.
• total fix time is around 2 hours (people talk of 15 mins. etc, but this is a little tricky with the fishing cable)
Legal Action Against Mercedes-Benz
SL Fuel tank needed urgently for our court case inspection. We are in the middle of a court case involving the
issue with the SL fuel tank problem with the buffer. My old tank was needed for the independent inspection but
regrettably was discarded by my garage. So to all of you out there let me know who has one or about to replace
his old one. We need it very urgently and I am willing to come and collect it. I donʼt have to tell you what will
happen if we win and I am very confident.
Erik Hoffman
07802 302302
erikhoffman@live.com
UPDATE - Judge Awarded against Mercedes-Benz UK

Interior - DIY Advice and Part Sources
Airbags
If airbag light come on
Heated Seats
Faulty heated seat :
• Check out fuse
•
Front Seats Motorised Function
Note : Only the driver's seat goes
Front Seat Removal
Removing the seat is really
Exit-Entry Convenience Feature

CD will not Eject
I had the same problem (found out later that there were 2 discs inside the slot). Try this, helped me, before You
take for repair: Lift the lid of the slot. You´ll see a small white plastic pin on left side ( I think there´s similar on the
right side too ). Take a small screwdriver and push gently the pin ( it should move about 1/2 inch ). Now at same
time push the eject button. That way I fixed mine, while my dealer could not do anything.
Steering Wheel Removal
Do not activate the ignition with the air bag disconnected. If you do, it will put the SRS light on (dealer has to
remove it).
• unlock the car
• make sure wheel is central and fully extended out to give clearance for the air bag side screws
• keep the key well away from the car and purge the electrical system (i.e 30 mins to 1hr after running
engine). (the air bag is an explosive device triggered by a electrical current, when you switch the car off
there is still an electrical charge available due to capacitors in the system hence you leave it off to
discharge any excess charge or in the very rare cases playing around taking it off might trigger it)
• using a torx 30 bit 2” long, undo the two air bag screws
• remove air bag
• disconnect both multi plugs, by releasing the catches on the plugs (one is steering wheel controls, the
other is the air bag)
• store air bag face upward (not the other way, as if it goes off it will launch itself where ever)
• using a 10mm hex key and wrench remove centre bolt
• mark the wheel and spline, so that the wheel goes back on in the correct place
• remove wheel
Installing New “Flat-Bottom” Steering Wheel
Original Steering Wheel!! 375 mm (14.75") dia.

Model Year 2009 Up (SL63 & SL65) Flat-Bottomed Steering Wheel
Question : Can anyone confirm if the newer, flat-bottomed-style steering wheel (2009 and newer) will mount to
the model year ʻ08 and older model SLs?
Answer : I've asked my dealer about this, and they said it is possible to do the conversion.

Electrics - DIY Advice and Part Sources
SL55 AMG - Batteries & Charging Overview
NOTE 1 : discharging a battery to a point too low will damage the battery.
NOTE 2 : SL55 AMG dual battery systems are separate (according to the wiring diagrams). You require to
charge both separately (i checked that the starter voltage does not rise while charging the system/consumers
battery).
NOTE 3 : when “jump-starting” only use front battery (never use rear one).
There are two batteries in the SL55 (front - starter battery only; rear - system/consumers battery used for
everything else).
The starter battery is dedicated to starting the car, so depletes quite slowly.
The system/consumers battery requires more frequent charging, as it continues to draw down while standing,
depleting rather quickly (about 0.14 volts per day).
It appears that Mercedes-Benz split and separated the batteries, as so many people store their cars for long
periods, which would have rapidly depleted the starting battery (lots of electronics in the car). These two
batteries are connected through a battery control module, which regulates the charging and discharging of the
two batteries, as well as handling load management. The battery control module measures the load capacity of
the main battery, actual current flow to loads, and can take active measures to stabilise the electrical system.

These measures include increasing idle speed, connecting the auxiliary battery to the system via a relay. or
shutting off nonessential consumers through the CAN Bus. This means that, under certain electrical conditions,
some electrical features may not work, while at other times they function normally".
Starter Battery

System/Consumers Battery

CTEK Battery Charger
Batteries need to be maintained with a battery tender if the vehicle is going to sit for more than a few days.
Mercedes-Benz, Porsche, Bentley and others, sell this CTEK identical tender kit (except with their own label),
and charge over $300 (locally purchased for around $70).
I had standard Mercedes-Benz rear system/consumers battery problem, which on research, discover is an
unsolvable Mercedes-Benz factory issue. If the car is used daily, then there are no no problems, but if car left
sitting for a few days or more, the system/consumers battery will be depleted with everything “off-line”, until it is
driven a few miles, to recharge system. Note, main starter battery (up front) holds its charge well.

If you have to leave your car sitting for any length of time, buy two CTEK battery chargers (separate ones for
front and rear batteries), and using their “quick disconnect” pigtails, plug them in every time the car is garaged.
Make sure you have to step over one of the charger cables, each time you go to the car, or else you may drive
away with the trickle chargers still connected.
Connector Cleaner and Protectant
Use Stabilant-22 (an electrical connector cleaner and protector).
Disable Intermittent Alarm
The alarm siren (mounted beneath the driver's side fender) can go off intermittently. This is due to its own 2
batteries going bad. When they go bad, they leak battery acid all over the circuit board, corroding it, and leaving
you with alarm issues.
There are two ways to fix :
Fix 1 :
• remove left front wheel
• remove the rear part of the inner fender liner
• reach inside (under the fender) and remove the siren.
• I decided to remove it with the bracket (3bolts as it seemed the easiest).
• You can buy a replacement for $103 and replace later if required
Fix 2 :
• In the main fuse box you will see a row of fuses.
• removing the 3rd fuse from the left should disable the alarm siren and nothing else
• this is a 7.5-amp fuse
Electrical Fault Finding - Theory
3 tangible items are important to remember when testing for electrical faults :
• power source - battery, alternator, plus side, power side, hot or positive.
• load device - any component that uses up voltage or has resistance to electrons flowing through a wire i.e.
motors, relays, lights, solenoids, coils, spark plugs, or ECUs.
• ground return - provides a route for electrons (electricity) to flow back to the battery after use by a load
device i.e. wires, metal body panels, engine block, transmission or vehicle frame.
All are necessary and must be present in a circuit in order for it to operate.

The power source, load device and ground return are physical objects, but in addition, there are basic 3
intangible properties of a 12 volt DC system :
• Voltage (Volts) - think of electrical pressure.
• Amperage Amps) - think of the amount of electricity used.
• Resistance (Ohms) - think of the restriction on the flow of electrons through the circuit.
Equations :
• Volts = Amps * Ohms
• Ohms = Volts / Amps
• Amps = Volts / Ohms
• Watts = Amps * Volts
• Amps = Watts / Volts
Series Circuit Rules
• All available voltage in a series circuit will be used up by the load.
• When more than one load device is present in a series circuit, the individual resistance of each load
device, divides the available voltage, thus adding to the total resistance of the entire circuit.
• Amperage is the same at all points throughout a series circuit.
Parallel Circuits
Nearly all circuits designed for cars are parallel circuits, and fortunately the rules are basically the same as for
series circuits, with two exceptions :
• Voltage will be equal everywhere on the positive side of the circuit and will not be divided between load
devices.
• Each additional load device lowers the total overall resistance of the circuit and increases amperage.
Copper Wire Gauge Chart
When the wire gage is decreased by 3 gage numbers, its cross sectional area is doubled and its resistance is
cut in half.
Wire Testing
The copper strands that make up a length of wire can sometime be the source of a voltage drop. Donʼt try to find
with your ohmmeter, but keep the wire plugged into the load, and voltage drop test the entire length of wire :
1. Set the voltmeter to read millivolts or on the lowest volt scale.
2. Put the voltmeter positive lead on the end of the wire closest to the battery.
3. Put the voltmeter negative lead on the other end of the wire.

4. Operate the circuit.
5. If the voltage drop is more than .100V (100mV), the wire, or connections are bad.
6. If excessive, remove the wire at both ends and clean the connections, retest.
7. If still excessive, replace the wire.
Wiring Colour Translation for Italian Cars
Find and Fix Short Circuits Faster (old headlight trick)
Fuse-popping shorts in electrical circuits can be hard to locate.
Home-Made “Short Circuit” Tester
• Grab a single filament sealed beam headlight unit
• Attach a couple of old coiled meter leads to the headlight terminals (a length of heat shrinkable tubing at
one terminal prevents a short circuit at the sealed beam electrical connections)
• Install wire ends the same size as the fuse blades at the other end of the test leads
• Add an inline fuse holder on the red wire (just to play it safe)
• Add wire ends on the opposite ends from the headlight unit, making sure they will slide easily but snugly
into the vehicle fuse receptacles
The procedure to find a short is simple and effective :
• Remove the burned fuse.
• Plug the sealed beam leads into the fuse terminals in place of a new fuse.

• Turn the circuit on and start looking for your short.
If normal load (in this case a bulb) is off, and the fuse is blown, installing another fuse would cause it to blow
again. We need some way to keep the circuit live while we test, and provide immediate feedback while we
eliminate the short. This is where this DIY tester comes in handy.
When you connect the headlight tester, if the short in the circuit is still present, the headlight will illuminate, telling
you that there is a short to ground on the feed side of the circuit in the wire between the fuse and the normal
load (one terminal at the fuse box supplies voltage, while the short provides ground).
This is a big diagnostic plus, since the circuit is live, and stays live as we start tracking the short, by wiggling
wires and wire harnesses. We'll know we've isolated or eliminated the short when the load starts working again.
We are putting the short to work, helping us locate the problem. The sealed beam lights because of the short. As
soon as we eliminate the short, the small bulb illuminates and the sealed beam will dim or even go out.
Bad Grounding (always check for this before Voltage Drop)
Because ground circuit voltage drop can cause most electrical symptoms, test grounds first :
• Connect your DMM between the engine and negative battery terminal
• Safely disarm the ignition (on some distributorless ignition systems, the simplest way to prevent the
engine from starting during the ground test is to pull the fuel pump fuse)
• Crank the engine for a few seconds.
• If the voltage drop is excessive, repair the engine ground circuit and retest.
• Next, connect the DMM between the negative battery terminal and the vehicleʼs firewall.
• Then start the engine and switch on all the major electrical accessories.
• Too much voltage drop? Then fix the body ground and retest.
Because computer circuits operate on such low current, the standard ground tests may not reveal a marginal
ground on an on-board computer. Before you condemn any on-board computer, check its grounds first. Operate
the computer system and back-probe each computer ground terminal. If you measure anything greater than 0.10
V, trace that ground circuit and locate the problem.
Sometimes, computer grounds are connected to a spot where they are easily disturbed or prone to corrosion,
such as a thermo- stat-housing bolt. Computer connector terminals also can corrode. Removing the connector
and spraying the terminals with electrical cleaner may be all it takes to eliminate the voltage drop. Experience
shows that as little as 0.30 V on a computer ground terminal can cause trouble. Try pinpointing that with a test
light.
Keep your eyes peeled for missing body grounds (if someone else worked on the vehicle, he may have forgotten
to reconnect body ground wires or cables). Remember that when the body ground is restricted, current tries to
find another route back to the battery. Under periods of heavy current flow, a restricted body ground may hamper
or shut off a component. For example, turn signals have been known to stop blinking when the driver steps on
the brake pedal. Testing confirmed that a restricted body ground choked off the turn signals. The ground could
not handle current from the turn signals and brake lights at the same time.

Relays
Overview of Relays
Here's a diagram of a Bosch relay. They come in many types, and are used in quite a few different vehicles.
When power is applied across the 85 and 86 terminals, current flows through a coil of small wire. This wire is
about 100' long, and is usually 28 gauge wire. This builds up a magnetic field in the bar it's wrapped around, and
the steel plate snaps to it. When the power is off, the spring pulls the plate back away from the magnet bar. The
"click" is the plate slamming into the magnet as it turns on. It doesn't "click" when turned off, because the plate
swings away from the magnet without hitting anything.
Note: When the power is applied, the coil sets up a magnetic field in it's windings. When the power is removed,
the field collapses, and a reverse current of high voltage will "kick back" This is called counter EMF, and is how
your ignition coil works (if your fingers are across the coil terminals when the power is removed, you will get a
shock).
Below are a couple of circuits to help understand how the relay works in real life. Relays are used to transfer
high current. A Lot of vehicles make use of the ground-to-turn-on circuit. If one if the relay coil terminals have
battery power all the time, the ground-on circuit is how it's wired. Most horn relays are wired in the ground-on
method. The steering wheel contact touches ground and turns on the horn. The horn relay is used because the
15-20 amps from the horn would arc and quickly destroy the contacts in the steering wheel.

Relays Explained in Detail
Relays are used throughout the automobile. Relays which come in assorted sizes, ratings, and applications, are
used as remote control switches. A typical vehicle can have 20 relays or more.
Relays are located throughout the entire vehicle. Relay blocks, both large and small, are located in the engine
compartment; behind the left or right kick panels, or under the dash are common locations. Relays are often
grouped together or with other components like fuses or placed by themselves. Relays are remote control
electrical switches that are controlled by another switch, such as a horn switch or a computer as in a power train
control module. Relays allow a small current flow circuit to control a higher current circuit. Several designs of
relays are in use today, 3-pin, 4-pin, 5-pin, and 6-pin, single switch or dual switches.
All relays operate using the same basic principle. Our example will use a commonly used 4 - pin relay. Relays
have two circuits: A control circuit (1 to 3) and a load circuit (2 to 4). The control circuit has a small control coil
while the load circuit has a switch. The coil controls the operation of the switch.
Current flowing through the control circuit coil (pins 1 and 3) creates a small magnetic field which causes the
switch to close, pins 2 and 4. The switch, which is part of the load circuit, is used to control an electrical circuit
that may connect to it. Current now flows through pins 2 and 4, when the relay is energised (below left).

When current stops flowing through the control circuit (above right), pins 1 and 3, the relay becomes deenergised.
Without the magnetic field, the switch opens and current is prevented from flowing through pins 2 and
4. The relay is now OFF.
“Normally Open” relays (above) are the most common in vehicle applications. However, relay variations include
three and five pin relays :
• 3-PIN relay instead of two B+ input sources, has one B+ input at pin 1. Current splits inside the relay,
supplying power to both the control and load circuits.
• A 5-PIN relay has a single control circuit, but two separate current paths for the switch :
• When the relay is de-energised or OFF, with no current through the control coil (pins 4 and 5 have
continuity).
• When the relay is energised or ON, with current flowing through the control coil (pins 3 and 5 have
continuity).
3 - PIN 4 - PIN 5 - PIN
Below are two popular standard MINI ISO relay configurations. The size of a ISO Standard MINI relay is a 1"
square cube. Both 4 and 5 pins designs are used.
5 PIN MINI RELAY
4 PIN MINI RELAY

Circuit Identification
Relays are easy to test but often misunderstood. Using a 4 pin relay for our example, we must first identify the
pins. Some manufacturers place a diagram and pin ID on the outside of the relay case to show which pins are
part of the control circuit and which pins are part of the load circuit.
If the relay is not labeled, use an ohmmeter and check to see which pins are connected to each other :
• You should typically find an ohm value of approximately 50 to 120 ohms between two of the pins (the
control circuit). If the coil is less that 50 ohms it could be suspect.
• The remaining two pins should read OL (infinite) if it's a normally open relay, or 0 ohms (continuity) if it's a
normally closed relay. If the readings are correct, proceed to the next test.
Note: If none of the relay pins showed a coil value and all pins show OL or 0 ohms, the control coil is damaged
and should be replaced.
Practical Testing
Once the pins have been identified, energise the control circuit by supplying B+ to pin 1 and a ground to pin 3. A

faint "click" will be heard; although this "click" means the switch has moved (closed), it does not mean the relay
is good. The load circuit switch contacts could still be faulty (high resistance), and further testing is required. A
common mistake technicians make is they hear a "click" and assume the relay is good. Take the extra step and
verify operation.
Operational Check With Test Light
Now start the second part of the test :
• Energise the relay (control side) by supplying B+ to pin 1 and a ground to pin 3 (a click should be heard).
• With the relay still energised, supply B+ pin 2 of the load circuit (the test light will be on).
• De-Energise (remove B+) the control circuit at pin 1 (the test light at pin 4 should go off).
A test light is preferred because a test light will draw current through the switch.
Operational Check With Multimeter
The following steps can be used to perform the testing of the relay using a multimeter :
• Keep the multimeter in the continuity check mode.
• Check for continuity between the N/C contacts and pole.
• Check for discontinuity between N/O contacts and the pole.
• Now energise the relay using the rated voltage (for example use a 9V battery for energising a 9V relay,
and the relay will engage with clicking sound).
• Now check for continuity between N/O contacts and pole.
• Also check for discontinuity between N/C contacts and pole.
• As a final test, measure the resistance of the relay coil using a multimeter and check whether it is
matching to the value stated by the manufacturer.
Voltage Drop Testing Explained
Symptoms of voltage drop
Often confusing and contradictory, electrical voltage drop symptoms vary according to the circuitʼs job and the
severity of the voltage drop :
• inoperative electrical parts
• sluggish, lazy electrical devices
• erratic, intermittent devices
• devices that work sluggishly or erratically during periods of high electrical loads

• excessive radio interference or noises in the radio
• damaged throttle or transmission cables or linkage
• repeated throttle or transmission cable failures
• damaged drivetrain parts
• engine or transmission performance complaints
• no-starts or hard starts
• high sensor or computer voltages
• erratic engine or transmission computer performance
• false trouble codes in the memory of any on-board computer
• premature or repeated A/C compressor clutch failure.
This symptom list brings up several points :
1. Visual inspections miss most cases of electrical voltage drop. You usually canʼt see the corrosion inside a
connection or the damaged wire that is causing the problem.
2. Ground-side voltage drop, a commonly overlooked cause of electrical trouble, can cause most of these
symptoms. Any circuit or component is only as good as its ground.
3. The more sophisticated electrical systems become, the more important their grounds are. The number of
electrical components has increased exponentially and most do not have separate ground wires. Instead, these
devices are grounded to the engine or body. Rust, grease, vibration and/or careless repairs often restrict the
circuit from the engine/body back to the battery.
4. Many components such as engine sensors share a common ground. Therefore, a bad ground complicates
diagnosis because it affects several components at once.
5. Some shop manuals and diagnostic charts or fault trees recommend checking grounds last. In reality, it is
much quicker to check ground circuits before you climb that fault tree.
6. Itʼs quicker and smarter to routinely check a circuitʼs voltage drop than it is to memorise long lists of
symptoms. If experience has taught us nothing else, itʼs that chasing symptoms is no substitute for routine and
thorough volt- age drop testing.
The presence of a bad connection (bulb) adds resistance, lowering the available voltage and amperage
necessary for the intended load devices (headlight or taillight) to operate. Replacing a headlight, taillight, or
battery will not solve this problem. The only way to repair this is to find the bad connection.
The trick is to find the bad connection without unravelling the wiring harness or removing parts. This is the done
by "Voltage Drop Testing".
Voltage Drops-Good or Bad?
Voltage drop tests are usually performed to test loads and locate circuit problems. As a result, we may have a
tendency to think of voltage drops as bad things. But voltage drops can be good or bad; it all depends on where
they occur in the circuit, and whether they operate loads, or simply waste energy.
Good voltage drops are essential. Loads wonʼt work without them. Available voltage must be dropped
across the load, or it cannot work.
Bad voltage drops allow available voltage to be “dropped” at a high resistance elsewhere in the circuit;
this steals electrical energy from the load. A bad voltage drop in a circuit converts electrical energy into
heat.
Unwanted resistance in the circuit reduces the amount of electrical energy delivered to the load.

Causes of unwanted resistance include: loose connections; corroded connections; broken wire strands; pitted
relay contacts; and other physical damage that resists current.
Diagnosing Voltage Drop (Locating the Bad Spot)
One of the most rampant electrical maladies showing up in automotive service bays today is the phenomenon
known as voltage drop. Left unchecked, voltage drop causes countless unsolved electrical mysteries, especially
when it infects the ground side of a circuit. It can also trick you into replacing parts that are not bad. The more
connections and wiring a vehicle has, the more vulnerable the electrical system is to voltage drop.
To contain electrical voltage drop, practice safe electrical service. This means measuring voltage drop before
reaching any conclusions. “Voltage dropping” a circuit will tell you when the circuit is too restricted to operate a
component (motor, relay, light bulb, etc.) or operate it correctly. If the circuit is restricted, repair it and retest. If
there is no restriction and the component still does not run or run correctly, then replace the component.
In a good circuit :
• Around 12 volts should always present anywhere between power source and the load.
• Around 0 volts should only show anywhere between the load and the ground return.
Poor electrical connections are the most common cause of electrical problems. "Voltage Drop Testing" is a
simple way to test for bad connections, switches, components, cables, wires, terminals, or relays, It measures
resistance within a circuit using a voltmeter (not an ohmmeter, as it can only tell you continuity, and not quality of
connection). The major advantage is that nothing needs be disconnected in order to perform the test.
Remember, the circuit needs to be tested dynamically, with current running through the circuit being tested.
If a minimal drop in voltage of 0.1 volts at the connector, this indicates there is no excessive resistance to current
flow, and thus the connector is good.
However, if the voltage measured across the switch is 0.4 volts, there is a problem with the switch, and it is
causing the light bulb to dim.
Simply cleaning the switch terminals and/or replacing the switch, will lower its resistance and increase the
voltage going to the bulb, thereby making it brighter. This method of moving the voltmeter test leads along them
to locate the point of high resistance will work on any circuit. The entire length of both positive and negative
sides of the circuit can be checked without disconnecting any wires or connectors.
Basics of Voltage Drop Testing
We can test available voltage with the load turned off, but available voltage will not tell us if the load will work in
the circuit, so we need to turn it on and then test it, as we can only measure voltage drops when there is current.
Step 1 — Test at the Load

• Set your meter to measure volts DC
• Connect your test leads directly across the load and turn it on.
• Take your reading.
Ideally, the voltage drop across the load should be the same as (or close to) the voltage available at the load.
• If this is the case, the voltage drop is a good one.
• If voltage drop across the load is a lot lower than available voltage, then the load wonʼt work properly,
because there is a voltage drop in the circuit somewhere denying the load the power it needs.
It isnʼt always practical to test right at the load, as you may not always have direct access to the load. For
example, you cannot connect your meter leads across the terminals of an in-tank fuel pump.
Step 2 — Test the Circuit
To test the circuit for voltage drops, connect your meter leads to two points in the circuit that have the same
polarity. For example :
• Connect one meter lead to a battery post and the other lead to the battery cable end (see illustration
below).
• Connect your meter lead between the positive battery post and the hot side of a fuel injector. Then turn the
circuit on and read the voltage.
Any voltage displayed on the meter indicates a voltage drop, and tells us exactly how much of the available
voltage never reaches the load. Assuming the meter leads are good, lower readings are better.
Know Your Circuit (any rheostats or ballast resistors, etc.?)
We need to offer a word or two of caution here. In some vehicle circuits, a resistor is intentionally inserted to
reduce voltage and current available to the load. Examples include the rheostat that dims the dashboard lights,
ballast resistors in some fuel injector circuits, and motor resistors used to limit blower fan and electric fuel pump
speeds. Be sure you identify an “intentional” voltage drop by checking circuit construction in a wiring diagram.
Voltage Drop Testing Good Values (to be expected)
Close to the following values, should show for good circuits. Use as a rough reference while testing "Maximum
Voltage Drop" :

Starter Circuit
Positive side small starter(4-cyl) = 0.3 volts; larger starter(8-cyl) = 0.5 volts
Negative side 0.4 volts
Starter Solenoid 0.2 volts
Battery Terminals 0.2 volts
Starter circuit (including starter solenoid) ! ! 0.60 volt
Battery post to battery terminal end ! ! ! 0.0 volts
Battery main cable (measured end to end) ! ! 0.20 volt
Starter solenoid ! ! ! ! ! 0.20 volt
Negative main cable to engine block ! ! ! 0.20 volt
Negative battery post to starter metal frame ! ! 0.30
Battery positive post to alternator b+ stud! ! 0.5 volt (all accessories turned on)
Battery negative post to alternator metal frame !! 0.20 volt
Charging Circuits
Positive side - alternator charging at 40 amps = 0.3 volts
Positive side - alternator charging at 100 amps = 0.7 volts
Negative side - 0.4 volts
Accessory Circuits (Headlights, Brake Lights, Taillights, etc)
Positive side - 0.2 volts
Negative side - 0.2 volts
ECU Circuits (Ignition Modules, Fuel Injection Sensors, etc). Note : Computer circuits are low amperage.
Positive side - 0.1 volts
Negative side - 0.06 volts (Very sensitive to loss of voltage)
Starting Problems
• Make sure your battery is in excellent shape without any corrosion on the terminals.
• Rule out an ignition switch problem by direct shorting of solenoid, to get the starter to crank, thus
bypassing the key switch.Now you have narrowed down the problem to the solenoid or the key switch or
wires in between or the battery and its wires.
• If the battery is weak, and you have corrosion on wires, weak contacts and high resistance in the key
switch, you get the primary coil juice to the solenoid to click, but not enough to make a complete circuit for
the secondary big current that shorts the solenoid and makes the whole this work by completing the circuit
through the starter.
• If the solenoid is bad or overheated, the body of the solenoid expands and can change the bore diameter
such that the centre core that completes the solenoid circuit does not move freely, i.e. it clicks but no
complete circuit.
• Use a good remote battery, and wire one lead to the solenoid terminal that goes to the key switch and
attempt to trigger the solenoid directly with the loose wire on the other side of the battery.
• If this works, you are not getting enough juice to the solenoid, which means your solenoid works, but not
your key switch or battery.
• If you are hearing a "big click" coming from the engine compartment that is most likely your solenoid. The
solenoid is engaging but the starter is not turning. (The solenoid acts a both as both a relay to switch your
battery voltage to your starter which takes very high current, and as a mechanical plunger to engage the
starter gear to the flywheel of the engine.) There is nothing in series electrically, temp switch etc., between
the solenoid and the starter.
• If the solenoid is making the "big click" then either, the starter is not receiving any or not enough battery
voltage to turn, or the starter has an intermittent open circuit.
• You should be able to regularly leave your car sitting for longer than 3 weeks, without having the battery
go flat, but for added security, use a small automatic battery charger and mounting it inside the car by the
battery and plug it in when garaged to provide a maintenance charge on the battery. Investigate the
condition of your battery/charging system/electrical, if the battery drains at rest.

• Italian cars with front batteries and rear engines, tend to suffer a lot of starter problems (that big cable that
is connected to your (+) pos. battery terminal goes directly to your solenoid, and the longer the cable, the
more voltage loss).
• If your are jump-starting from another car, connect the (-) neg. cable going to the good battery directly to
the engine block, or if you have charged your battery, connect a jumper cable from the engine block
directly to the (-) neg. battery terminal.
• If it starts, the ground strap going to the engine, is either damaged, corroded or missing (this is an noninsulated
flat mesh attached somewhere on the engine block to the chassis). Remove it, clean it up or
replace it, reinstalling, making sure all contacts are absolutely clean.
• If it doesn't start, check that the solenoid is switching voltage to the starter (it must be done with a fully
charged battery).
• The solenoid is the short cylinder attached to the back of the starter, with two bolts on the back and wires
attached (top one has the large diameter battery cable and a wire to the alternator, the other bolt has a
cable or flat mesh which goes inside the starter).
• Duplicate what should be occurring in the solenoid, by using a couple of screwdrivers, to short these two
bolts together (careful not to touch any other metal on the car) and causing a direct ground to the battery.
The starter motor will spin, but will not turn the engine since the solenoid has not engaged the starter
motor to the flywheel (you will probably create lots of sparks due to the high current but it is still a safe
12VDC).
• If starter spins, your solenoid is not transferring enough voltage to the stater (bad or corroded contacts
inside or outside the solenoid).
• If starter doesn't spin, you have a bad starter.
Battery Replacement
Do not spend
Fuses & Relays

Fuses 1-27 (left side engine compartment)

Fuses 28-49 (right side engine compartment)
Fuses 50-77 (right rear locker behind seat) Fuse 78 (right side trunk)

Fuse IDs

Relays (left side engine bay)

Removal & Replacement of the Alternator
Removing & Replacing the Starter
ECU Removal
Suspension & Hubs - DIY Advice and Part Sources

NOTE :!! For the “Tandem Pump” which feeds both the ABC and the Power Steering Systems, please
! ! refer to the details, alternatives, and costs for this pump replacement here (further down below)
! ! in this section.
Vehicle Height Level Control Button (left side rear on centre console)
• Both indicator lights off - normal lowest height setting selected
• One indicator light on - mid level setting selected (+0.6” or 15mm)
• Both indicator lights on - top level setting selected (+1.0” or 25mm)
Some say that by leaving it set in the top height position, this locks the valves in position, keeps the pressure up,
and also reduces wear and tear on the valves, while others advise that the car should not be stored for over 24
hours in the “2 light” highest height position setting, as this can promote strain on the system.
However, the consensus of opinion is that there is no problem raising and lowering as required (in fact the ABC
system continually automatically adjusts the ride height at varying road speeds), as this is not putting extra wear
on the system, and is in fact good for the ABC system.
ABC Sport Control Button (right side rear on centre console)
• Indicator light off - softer regular driving option selected
• Indicator light on - stiffer sporty driving option selected
The ABC sport setting does not change the suspension feel/stiffness as far as the dampening rates. It simply
changes the rate at which body roll is countered. The head of Mercedes spring/damper development, has been
quoted as saying about ABC specifications :
• Body roll during cornering is reduced by 68% with light off, while with light on in ABC Sport mode, body roll
is reduced by 75%.
• In either mode, braking dive and acceleration "squat" is all but eliminated.
• Body stabilising time after a rapid swerve is cut by 30%.
ABC Problems and Solutions
The things that are weak on the SL55 and will break (at around 100,000 miles) are (in no particular order) :
• front ABC strut/shocks $1,200 ea - ($1,500 - $2,000 ea dealer installed)
• rear ABC strut/shocks $1,000 ea - ($1,300 - $1,700 ea dealer installed)
• ABC valve blocks $1,100 ea - ($2,700 each including installation)
• ABC tandem pump - power steering pump and ABC pump combined, around $1,800 new from parts
sources, but around $6,000 from dealer + 4-5 hours labour. As a space-saving measure the tandem pump
was engineered as one unit.
For example, the left rear shock is setting down after being parked within a hour or two. The dealer wants to
replace the the rear control valve for $2,700 (valve is $1,400). Then they said that the front valve may need
replaced as well for more $$$$. The car has done 56,000 miles.
When you first present with ABC problems, the dealer will routinely do a fluid flush/change and rodeo ($900), to
see if this will solve the problem, but 99% of the time, it is a waste of time and money. Youʼll still have to return to
the dealership to change valves, etc., as a very common problem. Get new later-style valves, as Mercedes has
new and improved valves from 2007?. The part numbers have changed but I think it is 2203201258.

What happens is that the valves stick and can also have internal leaks. Make sure you go to a reputable
mechanic. If the proper procedure is not performed Mercedes will not warranty the valves.
Preventative Measures for ABC
• It is commonly found that the ABC will stay up almost indefinitely, by leaving it set in the top height
position. This locks the valves in position, keeps the pressure up, and also reduces wear and tear on the
valves.
• The ABC system is a costly system, and experts recommended that you have system flushed at least
once a year if driven a lot, or at least every two years if you donʼt drive a lot. Note, even though flushing is
expensive if done properly with the SDS and replace the filters on maintenance services, itʼs a lot cheaper
than replacing struts , blocks pumps etc.
• Cars that have ABC problems, seem to sit unused for long periods of time. This is just asking for leaks,
and not limited to the ABC system.
Valve Blocks

Valve Block Front
Formerly 220 320 03 58 (updated number is 220 320 12 58)
Valve Block Rear
Formerly 220 320 03 58 (updated number is 220 320 12 58)
ABC High Pressure Expansion Hose
Leaking ABC
Fairly common for the ABC fluid to leak. Most leaks come from the valve block situated in the front section of the
near side front wheel. The problem is that aluminium washers are used under brass pipe fittings, when copper
should have been used. The metals react when wet and the aluminium corrodes away causing the washer to
leak.
A very poor situation from Mercedes-Benz, from the engineering side and those that designed it should have
known better. Mercedes-Benz saved a lot of money by using aluminium over copper (about 5p per car). It never
fails to amaze me, that a such a company will try to save money, on such a cheap item in particular, when they
like so much to boast about their engineering prowess.
Replacing Aluminium Washers With Copper
• Obtain copper washers (if thicker, it doesnʼt matter.
• Tools required are a 10mm socket (for all of wheel arch liner), 10mm open ended or ring spanner (for the
valve block), 19mm open ended spanner, and 1 litre of MB ABC fluid ($13).
• First you need to get all 4 wheels off the ground and the car on axle stands (the wheels can stay on apart
from the front nearside)

• The idea is to stop losing all of the fluid in the system as the wheels are now hanging.
• In this particular case, we are working on the return line, so no major issues or pressures.
• You can access the block from underneath (easy with ramps) by removing the triangular cover below the
valve block rather than the wheel arch liner. That wouldn't be so easy on axle stands but it meant the
wheel didn't have to come off and possibly a good bit faster if you have the kit. Otherwise, remove the
wheel arch liner.
• When you gain access to the block, youʼll find this mess (image below), which must all be washed down
with an degreasing spray and hosed off (so that you can see the leak).
• Most of these leaks are within the fluid return pipes (this is the upper block of the 2 within the wing).
• There is the sensor in the centre of the front face and the valve on the side of the block that can leak
• In this case (image below) it was the valve on the side leaking, and you can see the hole with the valve
removed
• However, while you area at it, it is strongly recommended to replace both of the washers (the one on the
sensor and the one on the valve).

This is the valve and washer
• Refill the tank nearest the front (the round tank is the power steering)
• Start the engine and check for leaks
• If OK, switch engine off, re-fit the liner and replace the wheel.
• Next start the car again and press the raise button so that both LED's are on, and lower again so that they
are both off.
• Again, switch engine off.
• Remove the axle stands and jacks and start the engine again, refilling the tank, so that the level is up to
the middle mark on the dip stick.
• Always carry a spare litre of ABC fluid at all times, and youʼll always get home should a leak happen.
ABC Alternatives?
The Black Series SL65 uses a new adjustable coil-over suspension (KW Variant3), as opposed to the unnaturalfeeling
Active Body Control (ABC) used on all other SLs. Befitting the serious nature of the Black Series, the
suspension is quite stiff.

On the Black Series SL65, without ABC, when you do a "quick test" via the Star Diagnosis, there are current fault
codes in control units that have "this fault code can be ignored in Black Series models" after the DTC. Therefore,
it appears possible, to retrofit the coil-overs to other Sls. However, the tandem ABC pump may have to be
replaced with a power steering only pump. The only power steering pumps for V12s that do not have ABC are
from a Maybach or SL65 BS, and probably very, very expensive. I continue to ponder if coil-overs would be a
viable option when there is a catastrophic failure of the system, or if a fully adjustable suspension is desired.
Maserati does it on their cars.
KW Variant3 coil-overs (but could it be possible to fit a softer Variant1 or 2?)
Tandem Pump
Overview of “Tandem Pump”
The “Tandem Pump” feeds both the ABC and the power steering systems. This pump is compatible with
Mercedes-Benz SL55 AMG and SL500 (R230) form 2003 to 2006 (need to check 207on pump - may be this
later “ixetic”). As a space-saving measure for the SL these pumps were engineered as one unit (hence the
outrageous price). It is a problematic system since it was taken from the formula one side.

Mercedes-Benz OEM “tandem pump” (ABC Tandem Power Steering Pump):
• is a LUK ZF manufactured unit
• Manufacturer Part Number : 0034665001, 0034662701
• Interchange Part Number : 003 466 50 01 (updated?), 003 466 27 01 (note same as above with spacing)
Later Mercedes-Benz OEM “tandem pump” (ABC Tandem Power Steering Pump):
Need to research, but appears Mercedes-Benz used a later updated “tandem pump” from supplier “ixetic” (if you
look closely, at pump image below, you will see “ixetic” on the yellow label). The "Early" Pumps were made by
Luc. The "new" ones are made by Ixetic and the word is that the new ones are better made.
• Later new-style pump from the Dealer or a real Benz Part house is made by a company called “ixetic”
• Manufacturer Part Number : 541 0228 10
• Interchange Part Number : A 003 466 50 01

Valve Block Front
Formerly 220 320 03 58 (updated number is 220 320 12 58)
Valve Block Rear
Formerly 220 320 03 58 (updated number is 220 320 12 58)
Symptoms of Impending Failure
Pumps usually only last about 70,000 miles (112,000 km) as it is a constant running pump. Symptoms include :
• intermittent ABC system shut down between starts
• floaty ride
• intermittent red and blue ABC warning on dash
• Strong smell of “Pentosin” fluid
• Hydraulic fluid below car
• On checking the fluid dipstick, you may see some bubbles (denoting air getting in)
As soon as you encounter any of these symptoms, take the car immediately to the dealer, but if pump suddenly
bad or fails, stop immediately and have the car “flat-bedded: to the dealer (it is possible for the car to go all the
way down and fluid will overflow from the ABC reservoir, making the possibility of an engine fire very real). The
trick is to replace the pump, before you contaminate the system with debris from the pump. You donʼt want to get
the valve blocks and struts contaminated with pump shavings.
Costs and Alternatives
• New pump cost from Mercedes-Benz Dealer is roughly $6,000 Canadian + 4 hours installation (dealer
quoted).

• U.S. cost is around $675 for rebuilt pump and around $1,295 for new LUK ZF pump
• Canadian cost for a new pump is around $1,800 for LUK ZF pump.
• Canadian cost for a later new “ixetic” pump is around $?
ABC Summary
You are driving a very expensive car and unfortunately some of the repairs are comparable to the price of the car
when new. The good news is that once you get it all sorted out, you have another 5 years of driving a really
awesome car.
Brakes - DIY Advice and Part Sources
The cost of a brake job (parts and labor), in dealer, if it's just pads is around $250, rotors and pads $750. They
are actually pretty cheap to have done relative to a lot of cars in the same class.
I did the front brakes on my SL55 for $110/each for the front rotors and $200 for pads. Very cheap compared to
Ferrari parts!
NOTE : ! EBC pads (2=Greenstuff; 3=Redstuff; 4=Yellowstuff).!
! ! You can get EBS Green/Yellow/Red brake pads for about $100 a set.
Note : Low dust pads tend to be more prone to overheating, cause brake disc wear, and judde
Front Brake Pads
Used on ?.
L=?mm x H=?mm x T=?mm.
Rear Brake Pads

Used on.
L=?mm x H=?mm x T=?mm.
Front Brake Discs/Rotors
?" x! ?! ! ?mm x ?
Discs cost about $125 each from Auto Parts Warehouse.
Rear Brake Discs/Rotors
?" x ?! ! ?mm x ?
Discs cost about $125 each from Auto Parts Warehouse.
Squealing Brakes (DO NOT fit pads other that OEM AMG dealer pads)
Usually caused by poor aftermarket pads.
For example, a SL55 owner chose Textar pads as he had used them on various cars previously. However, after
installing on the SL55, he noticed that after the first few stops, they squealed very badly, and once mildly warm,
they squealed every time below about 10km/h. His solution :
• tried several hard stops from speed to "bed in the pads"... no change.
• next he took wheels off to ensure that springs and clips were correctly installed... all OK.
• removed new Textar pads and applied MB brake grease... no change.
• pads removed again, and chamfered with a slot cut as seen...no change.
• Last resort was to fit a set of genuine Mercedes-Benz pads.... Fixed the problem.
Below, shown the inferior quality of Textar pads :
Replacing Front and Rear SL55 Brake Pads
Note : front and rear pads on the SL55 have same changing procedure
You can change your own brakes on the SL (theyʼre all discs), but you require to first disable the Sensotronic
braking system (SBC), before working on the pads.
Disabling the Sensotronic Braking System

Method 1
Just disconnect the brake module/pump (in the front left of the engine compartment, with SBC on it, and it has all
the brake lines coming out of it). The harness easily unplugs from the SBC unit/pump, and you can start the car,
although the dash will go red and warnings will appear, but when the plug is back in, it will leave no fault codes
to be erased :
• slide the connector clip up
• then pull the harness to the left (your brakes will not explode when you disconnect them)
Method 2
You can also change the brake pads by disconnecting the consumer battery (boot/trunk) and pumping the pedal
a few times.
Procedure :
• Disable the SBC (as shown above)
• Make sure the parking brake is off (you will need this to change rear brakes)
• Remove wheel
• Put a large wrap of cotton cloth under the brake master cylinder (to catch any excess brake fluid)
• Drive out the two pad retaining pins, using a small drift from the front (keep these and the spring clip in a
safe place)
• Using brake piston spreader or a large flat screwdriver to carefully compress the pads away from the disc/
rotor (wedge the screwdriver in between the disc and pad backing plate, and GENTLY but FIRMLY ease
the pads off the disc)
• Once you get a small amount of space between the pad and the rotor, use a small(10") pry-bar or brake
piston spreader and gently press the piston into the calliper completely, being careful to not gouge the
rotor
• You can also use C-Clamps to push in calliper pistons (below) :
•
• Be careful to watch the fluid level and made sure the pistons do not extrude (even if the pads are down to
a few millimetres, the fluid level in the reservoir should not rise more than a few millimetres when the
pistons are pushed back)
• On one side of the car there will be a sensor from pad to a locator on the hub - remove it.
• Draw out the old pads
• Remove the anti squeal plates and put them all to one side for now
• Clean the pad sliding surfaces inside the calliper with a wire brush
• Note that the genuine new pads are chamfered/bevelled on the leading edge (towards rear of vehicle) to
help stop squealing. If using aftermarket pads, the leading edge of pads can easily be chamfered, with a
quick rub on the concrete sidewalk or under an angle grinder.

• Liberally spread some anti squeal paste on the back and edges of the new pad steel backing plate (do not
get any onto the pad surface) and refit the anti squeal plates
• Insert the new pads

• If you find that the new pads will not slide in, retrieve the old pads and slide one back in as it was, and
using the other end on as a lever, put it on the other side and again firmly lever back both pistons until
they are level with the calliper allowing the new pad to slide in. Leave it there, and using the old pad you
had in place on the other side, firmly lever back the pistons so the new pad will fit in. BOTH PISTONS
MUST BE WOUND BACK TOGETHER. If you do just one, the other will pop out.
• Replace the sensor wire on one of the pads with a new one that will be with the set of new pads
• Reinsert the spring plate/clip and retaining pins, and using a small punch, to tap the pins back into place
from the rear, and make sure that each pin 'clicks' into place. (Do not use grease or ant-seize on the pins.
Just keep clean and dry)
• Check fluid level and top up if required
• Remove the cotton wrapping from the brake master cylinder
• Reinstall the wheel
• Reconnect the brake module/pump wiring harness by plugging it back in
• Start car (you will notice all sorts of red warning lights and messages on the dash, but don't panic)
• While car is idling, step on the brake pedal several times to set the pads, while pedal is still depressed,
turn the steering wheel from lock to opposite lock TWICE. After about 30 seconds, all the warning lights
and messages will go away.
Replacing SL55 Front Brake Disc/Rotors
• Follow the section for removing brake pads in “Replacing SL55 Brake Pads” above
• Get a stand (a large paint can is good) that will fit behind the disc with the top flat just under the calliper
(this is to rest the calliper on after the next step)
• Behind the calliper there are two large 21mm bolts, holding it to the hub (these bolts are fitted with Loctite,
so they will be tough to undo, and you will probably have to use a long lever)
• Rest the removed calliper on the stand you have ready and move away from the disc/rotor
• Remove the small torx head screw holding the disc/rotor to the hub
• If you are lucky, the disc/rotor will pull straight off.
• If not, persuade it with a judicial blow of a large hammer, and failing that, try this method below (using an
improvised disc/rotor puller, wind the clamps up tight, then strike the disc/rotor on the hub face with a large
hammer, and "BANG": they fall off) :
•
•

• Fit the new disc/rotor by following the above steps in reverse
• Smear a film of copper grease on the hub face before replacing the new disc/rotor
• Refit the small torx head screw holding the disc/rotor to the hub
• Make sure you use some Loctite on the calliper bolts, and do them up TIGHT
• Follow the section for replacing brake pads in “Replacing SL55 Brake Pads” above, including plugging in
the SBC, and starting car, etc.
• Time involved, was probably 30 minutes per side
Replacing SL55 Rear Brake Disc/Rotors
• Follow the section for removing brake pads in “Replacing SL55 Brake Pads” above
• Now follow the section for removing disc/rotors in “Replacing Front Brake Disc/Rotors” above
• One of the reasons the rear disc/rotors are harder to remove, is that the parking brake mechanism is in
there (in fact, an old fashioned drum brake). If it has had considerable use, then the friction material will
have made a channel in the drum which acts as a lock
• Fit the new disc/rotor by following the above steps in reverse
• Smear a film of copper grease on the hub face before replacing the new disc/rotor
• Refit the small torx head screw holding the disc/rotor to the hub
• Refit a sensor on one side each of front and rear
• Make sure you use some Loctite on the calliper bolts, and do them up TIGHT
• Follow the section for replacing brake pads in “Replacing SL55 Brake Pads” above, including plugging in
the SBC, and starting car, etc.
• Time involved, was probably 30 minutes per side
Brake Fluid
2 pints of DOT4 brake fluid for flush.
Brake Bleeding Procedure (using my vacuum system)
• Make sure all brake bleeding screws are clean.
• Check fluid level in Master Cylinder (continue to do this frequently during the bleeding procedure).
• Either attach clear tubing on outside of bleed screw or insert correct size tapered adapter inside the centre
cavity of the bleed screw, using a pushing, twisting motion.
• Operate the vacuum handle about 8 to 12 times to create a vacuum in the line.
• Open the bleed screw slightly (1/4 to ½ turn) to allow fluid to enter the jar.
• Air that is bled from the system will appear as large, uneven bubbles in the clear tubing. Continue until no
more bubbles are visible.
Brake Dust
Try using Armour All Wheel Protectant aerosol spray (not wheel cleaner) to keep the brake dust at bay. It's pretty
amazing and you will find less brake dust on the wheels and it's easier to clean off. The key is to thoroughly
clean the wheels first, then thoroughly spray the Wheel Protectant liberally, then let it sit over night. If you miss
spots on the wheel you'll notice brake dust accumulating there. The brake dust seems to bead on the wheel and
that's why blowing it off with compressed air seems to work.
“Get Home” Kit

This kit is carried, in pouch, in front trunk. Consists of the following :
• A Copy of this file.
• Towing eye hook (screws in to front valance)
• Bulbs - Direction indicator - spherical 12v SAE type 1073/32 cp?
• Parking and stop rear lights - spherical double filament 12v SAE type 1034-3/32 cp ?
• Interior roof lights - cylinder 12v 10w ?
• Correct style of fuses ( 5, 8 and 16 amp)
• Carry set of relays
• 12v Circuit Tester
• Electrical Contact Cleaner (Use Stabilant-22 (an electrical connector cleaner and protector)
• Paper Towels
Buyerʼs Guide
There's a lot of love for the venerable Mercedes roadster. One of the best of the breed is the SL55 AMG, so
perhaps now is the time to consider taking the plunge.
The SL55 AMG was the most powerful road car ever built by Mercedes when it was launched in 2002 and,
clearly, one of the best SLs ever. It arrived in the UK in the summer of that year, following on from the R230
SL500 on which it was based, with 476hp from its 5.4-litre supercharged V8. The £89,040 SL55 covered
0-62mph in 4.7 seconds and had an electronically capped top speed of 155mph.
There was immediate speculation about the SL55's true top speed from the moment it was launched. To prove
the car's potential, one German car magazine removed the electronic limiter and drove an otherwise standard
SL55 to 202mph.
When Merc brought in its revised styling for the SL in 2008, it took the chance to drop the M113 5.4-litre V8 and
replace it with the M156 6.2-litre V8 to create the SL63. For this guide, we'll stick with the M113-powered SL55
that is far more plentiful and popular. Even with this popularity, however, early SL55 AMGs are now into the
affordable bracket from around £16,000, which makes them a fine performance bargain.
Powertrain
The SL55 AMG's 5.4-litre V8 may have been based on the SL500's, but very little of the less powerful, nonsupercharged
motor remains untouched. For starters, there's the belt-driven screw-style supercharger that sits in
the vee of the engine block. With Teflon-coated aluminium screws, the supercharger can spin at up to 23,000rpm
when the engine is at its limit. This rev limit for the engine is increased to 6,100rpm from the standard SL500's
5,600rpm ceiling.
To cope with this extra power and its associated stresses, AMG engineers adapted the crankcase to use special
transverse screws. The engine also runs with a strengthened block, uprated bearings and pistons with greater
resistance to heat and pressure. Also helping the motor to cope is an improved oil supply system with modified
sump and higher capacity oil pump.
The SL55's engine bore remains the same as the SL500's, but stroke for the AMG was increased from 84.0mm
to 92.0mm, giving the 5.4-litre capacity that is 473cc greater than the SL500's. Other changes made by AMG
include cylinder heads with revised intake and exhaust ducts, higher-lift camshafts with longer opening durations
and double springs for the valves.
Mercedes also used the SL55 to introduce fully computer-controlled engine mapping for the first time on its road
cars. Along with the SL55's twin catalytic convertors, it managed carbon dioxide emissions of 340g/km, which
were considered very reasonable in 2002.

Problems with the M113 V8 are very rare as it's a strong engine. Check the oil and coolant fluids are clean to the
level, and make sure all of the visible pipework is in good condition as access around the engine is tight. The
charge cooler for the supercharger sits in the engine's V and uses its own radiator, so have this checked for
leaks or corrosion. A squeaky supercharger can be made quieter by squirting some graphite spray down the
head of the supercharger. It's not a complete fix, but the supercharger is a strong unit and should give no
problems, even with an uprated pulley fitted from established tuners such as Kleemann.
Much more of a worry is the five-speed automatic gearbox, which also came with paddle shifts mounted on the
rear side of the steering wheel. On any test drive, check the gear lever slots from Park into Reverse, Neutral and
Drive cleanly. If there's any hesitation, resistance or it needs to be given a shake to make it work, the plastic peg
that prevents the lever inadvertently being knocked into Reverse without the driver's foot on the brake is about to
break. It's a relatively easy part to replace and there are direct replacements made from aluminium available that
cure the fault. A Mercedes dealer may elect to replace the entire unit, which can add up to £1,500 in components
and labour rates. The gearbox also needs its fluid completely changed every five years.
The rest of the SL55's transmission is very tough, though watch out for cars that have been used on track as the
AMG's weight will give every component a hard time. In normal mixed driving, the SL55 should go 12,000 miles
between services.
Uber-comfortable ride and clever stability systems, but watch for hydraulic leaks
Mercedes fitted its ABC (Active Body Control) as standard to the SL55 AMG, which allows the car to corner more
flatly yet retain a comfortable ride. It uses hydraulically controlled servos connected to the springs and dampers
and did away with the need for anti-roll bars. This didn't stop AMG's engineers coming up with improved,
stronger rear axle mounts, a beefier steel subframe and better spring links.
Undoubtedly a clever solution, ABC now poses a worry for potential SL55 buyers as the pipework corrodes and
lets fluid leak away. In turn, this lets the ABC's hydraulic pump run dry, which is usually the first component to be
blamed for the system failing. Check the pipes carefully and budget for replacement if there are any signs of
corrosion. In doing so, you may save yourself the cost of a new ABC pump, so check for any signs of fluid
leaking underneath the car.
Another leak to watch out for is from the fuel tank caused by a faulty fuel pump. Again, most will have been
replaced under warranty by Mercedes, but some cars were missed and are spotted by a ticking noise from the
tank when it's less than three-quarters full.
The SL55 was blessed with improved brakes over the standard SL range, gaining eight-piston callipers biting
into 360mm vented discs at the front. This set-up almost doubles the front pad face to 220 square centimetres
compared to the SL500. At the back, there are 330mm vented discs and early SL55s came as standard with
multi-spoke 18-inch AMG alloy wheels. Later cars were fitted with 19-inch twin-spoke alloys that are easier to
clean and less prone to kerbing.
You can expect the brake pads to last around 20,000 miles in normal driving, but they do wear more quickly than
most cars'. Discs will also need replacing more frequently than with many other cars of similar performance, but
the ESP and Emergency Brake Assist systems are reliable and hassle-free.
However, the Sensotronic Brake Control (SBC) was subject to two recalls early in the SL55's life. One was for a
software update to the ECU and the other was to check for problems with the brake's hydraulic system. A check
of any SL55's history file should tell if this work has been required and carried out, so don't buy any SL55 without
a complete history record.
Finally, tyre wear should not be any worse than for a comparably quick and powerful rear-wheel-drive car. The
front tyres are 255/40 R18 and 285/35 R18 at the rear for earlier cars.
Svelte styling and that folding metal roof
The SL55 that is part of the R230 generation has a steel monocoque. However, Mercedes made extensive use
of aluminium for many of the body panels to help keep weight down. This means a thorough check of the body
for dents and parking dings is essential as aluminium is trickier and pricier to fix.

The SL55 uses the folding metal Vario-Roof that incorporates aluminium to help reduce weight. While the roof
itself is no cause for concern, the seal between rear windows and body is, which leads on to problems with the
roof's electric motor, the central locking and alarm. When these seals fail, it allows water into the boot where it
gathers around the roof's motor. To make matters worse, Mercedes surrounded the motor with foam to insulate
the cabin from noise when the roof was being operated. The foam acts as a sponge, holding water around the
motor and causing it to fail.
When looking at any SL55, lift the boot carpet and feel for damp. Any signs of water are bad news and likely
mean you'll need to replace the electric motor. This is the root of all the stories about the SL's folding roof failing,
even though Mercedes tried to rectify the problem when the car was new. Some cars still suffer from this fault, so
inspect any SL55 carefully.
Mercedes finally cured the leaky roof issue in 2005 with redesigned seals and these may well have been retrofitted
to an earlier car you're considering. While checking the roof, also listen out for any rattles when the roof is
raised. It's not uncommon for the roof to creak a little, but it can be the sign of poor alignment from the factory or,
worse still, crash damage.
Distinguishing features for the SL55 from the outside are the 'Kompressor' badges on either front wing, a deeper
front splitter, side skirts and dual twin tail pipes for the exhaust. All body panels are readily available for any
crash repairs.
Plenty of leather and equipment underneath that folding roof
Mercedes didn't stint on luxury when it came to the SL55's cabin. Unique perforated AMG leather covers the
sports seats with extra bolsters for added support, while Alcantara is used on the instrument binnacle and front
edge of the gear lever. There's aluminium trim for the centre console and door trims, and it's also used for the
door sill plates with AMG logos.
The SL55 was offered with three interior options for the leather. They covered black and graphite, alpaca dark
grey and alpaca grey, and black and berry. For the instruments, AMG's unique script is used for the numbers on
the main dials, which have silver faces and red needles, and there are 'AMG' and 'V8 Kompressor' logos on the
lower part of the dials to remind the driver of what's under the bonnet.

From launch, the SL55 came as standard with Mercedes' Audio 30 stereo system, twin front and side airbags,
electric windows and climate control. All of these have proved to be trouble-free and the electrically adjusted
leather seats are hard wearing. However, it's worth tipping the seat backs fully forward to check the well at the
rear of the seats for damp. This is another area where water collects if the rear windows seals are faulty. Also be
sure the central locking and alarm function properly as their controls are in the boot next to the roof's motor that
is susceptible to water ingress from leaky window seals.
Most of the electronics in the SL55 are reliable, but press every button to be sure. The optional Command
satellite navigation may seem outdated now, but it's worth checking it works.
Some of the warning beeps in the SL55 can ping on, but several are over-sensitive, such as the alarm to tell you
the bonnet and boot are open. A good specialist with resolve these issues, and plenty of owners tell us
Mercedes dealers have improved their customer service considerably from the early days of the SL55.
Owner's views
"After many years of driving different cars, I eventually realised for me, and possibly others, the compromises
Porsche and Ferrari make to obtain outstanding lap times at the track do not translate into good cars for the
roads we have. So I thought back to the 55 AMG and realised it did everything you would need in a road car."
"The engine is generally bullet proof and there are owners out there with galactic miles on their cars."
"The comfort is superb in an SL55 AMG. It's a heavy car and doesn't handle quite as sharply as some sports
cars, but the Merc is a great everyday car as it does everything well, so long as you buy a good one from the
outset."
"On the inside, it's typically Mercedes: everything is close to hand and the fit and finish and switch quality are
superb. It's a tad Germanic-dull if you have sat in a Ferrari 360 or 430. If you feel the SL is lacking in occasion
opt for the panoramic roof that adds a special touch, but equally I love the Alcantara headlining with matching
Alcantara on the pillars and instrument binnacle."
High Mileage SL55
So far so good, nothing too expensive to fix yet. Now, I'm starting to freak a little though, ha ha, never know what
may be looming around the corner.

My Buyerʼs Checklist
Car & Seller Info
Sellerʼs Name ! ___________________________________________
Address ! ! ___________________________________________
! ! ! ___________________________________________
! ! !
! ! ! ___________________________________________
Telephone ! ! ___________________________________________
Car Make! ! ___________________________________________
Car Model! ! ___________________________________________
Asking Price $!___________________________________________
Date !! ! ___________________________________________
Car Info (From Initial Email/Telephone Contact With Seller)
VIN ! ! ! ___________________________
Mileage ! ! _________________Km __________________Miles
How Long Owned !__________________________________________
How Many Owners _________________________________________
Complete Records/Service History?! __________________________
Engine Oil Currently? _______________________________________
Where maintained/mechanic _________________________________
Original Colour! _________________________________________
Last Paint Job ! _________________________________________
Interior Colour! _________________________________________
Wheel Type/Sizes!_________________ Tire sizes _______________
Air Conditioning ! Yes / No
Automatic! ! Yes / No
Original Engine! Yes / No __________________________________
What special features or options does it have? ___________________

________________________________________________________
Exterior Condition! 1 2 3 4 5 6 7 8 9 10
Interior Condition! 1 2 3 4 5 6 7 8 9 10
Car Fax Report ! Yes / No ! ! Car Proof Report! Yes / No
May I bring the car to a place for inspection? ! ! Yes / No
Any Accidents?! Yes / No
Emission Test?! Yes / No
Safety Test?!! Yes / No
Why Selling!! ________________________________________
Long Distance - Have Seller Email the Following
• Copy of “Used Vehicle Information Package” - From Vehicle Licensing Centre
• If dealer get Copy of “Car Proof” & “Car Fax” reports, or if private buy reports
• Any "bad" records in the VIN history reports?
• Copies of receipts
• List of work/repairs done
• Check service history for repairs, oil changes, and scheduled maintenance (mileage proof)
• List of modifications/upgrades
• Pictures - Body from all angles, underneath, engine bay, trunk, interior
• If the car has been restored, ask for any pictures taken before, during and after
Follow-Up Questions to Ask Yourself After Youʼve Hung Up The Phone
• What's your gut reaction? ____________________________
• Does this car seem like a possibility? Yes / No
• Current owner seem like he cared for the car? Yes / No
• Why am I interested in buying "this" car? ________________
• What is the most willing to pay for this car? $ ____________
• What is the least car can be had for? $ _________________
Inspection and Test Drive
Bring :
• magnet (not too powerful)
• probe or small screwdriver
• flashlight
• spark tester
• mirror on a telescopic handle
• digital camera
• a mechanic (if not, make sure to arrange/pay for a pre purchase inspection)
Inspection Tips :
• Always inspect/take delivery of the vehicle in the broad daylight; never in the evening/night or in the rain.
• A clean piece of cardboard placed under the engine/trans after the test-drive will help show fluid leaks.

• Require seller have the vehicle pass all state inspections (safety, emissions) at a mutually agreeable shop
(NOT one of his choosing) before you pay for it. Old (>30 days) inspections are of absolutely no use to
you.
A general guide to reading exhaust smoke :
• Black smoke = unburned fuel (valves bad or out of adjustment? Carb out of adjustment?)
• Blue smoke = burning oil (Accelerating: Piston rings bad? Decelerating: Valve seats/guides bad?)
• White smoke = burning coolant! (Bad head gasket? Warped or cracked Head or Block? $$$)
Circle your ratings are as follows :
4! =! Excellent
3! =! Good
2! =! Average
1! =! Poor
1.!Exterior walk around
! ! ! 4 ! 3 ! 2! 1
Make sure the VIN matches other VIN's on the vehicle and paperwork (original / no alterations)
Does the car stand level?
Visually inspect for rust, repairs, damage, alignment, mismatched paint, overspray (magnet detects filler)
Open and close doors / hood / trunk / tailgate for proper operation
Inspect grill / trim / rubber moulding for bends or splits, dings, missing parts and proper attachment
Inspect the windshield / wipers and side and rear windows for damages, pitting, repairs, wiper marks or cracks
Does the car bounces too much when you push one of the corners down?
Damaged rims?
Do tyres have irregular wear (alignment problem)?
Are wheels and tyres correct size and tyres have good tread depth / pressure?
2.!Engine compartment
! ! ! 4 ! 3 ! 2! 1
Any oil, coolant or brake fluid leaks?
Is engine dirty or oily?
Check the oil for water / sludge / clarity / level
Check all fluid levels
Inspect belts for wear and fraying
Check hoses
Inspect wiring
Look for water pump leaks
Any indication of poor repair work / lack of maintenance? (e.g. badly corroded battery terminals, very low oil
level, etc.)
3.!Start the engine
! ! ! 4 ! 3 ! 2! 1
Check for smoke coming from the exhaust (slight water steam is OK)
Any warning lights stay on or come on while the engine is running?
Is the engine oil pressure too low at idle?

Is the engine idle and rev quality smooth when cold and hot?
Are there any noises (knocking, pinging, whistling, etc)?
Keep it running until the engine is hot, and check for exhaust smoke again
Check oil cap and dipsticks for signs of water. (oil off-colour, brown/grey/white or bubbly)
4.!Take the car for a road test.
! ! ! 4 ! 3 ! 2! 1
Listen for engine noise at high / low speeds
Listen for automatic transmission / transaxle noise
Is the automatic transmission shifting smoothly, any delays or trouble shifting?
Does the kick-down function work?
Listen for drive axle and transfer case bearings or gear noise / vibration (humming or growling noises)
Does the engine perform and accelerate properly?
Test the steering for responsiveness / smoothness / free play / pull aside / steering wheel centres
Test brakes for effectiveness / operation / noise / pulling / pedal feel / ABS warning light coming on while driving
Is water temperature and oil pressure normal when hot?
Any vibration between 90kph to 120kph (balance issues) or any humming noise (uneven tire wear)?
Do all lights, switches and gauges operate properly?
Excessive wind noise while driving?
5.!Check to make sure all exterior lights are operational.
! ! ! 4 ! 3 ! 2! 1
Head lights, high and low beams
Tail lights
Brake lights
Parking lights
Hazard lights
Reverse lights
Turn signals
License late lights
Fog/Driving lights
Check for cracked or clouded lenses
6.!Inspect the interior.
! ! ! 4 ! 3 ! 2! 1
Is the driver seat / steering wheel worn excessively?
Has the odometer any evidences of tampering?
Check the condition of seat upholstery and seat belts for wear / rips / cracks / fading / stains
Are the carpets / door panels / dashboard / headliner in good condition?
Check condition of glovebox, console armrest and door storage
Does the Radio / CD / Navigation work ?
Does the air conditioner provide really cold air?
Does heater / defogger / defroster work?
Does sunroof / electric windows / door mirrors / heated seats / tilt steering work?
Any dampness under the carpets?
7.!Inspect the Trunk

! ! ! 4 ! 3 ! 2! 1
Any dampness under the carpet in the trunk?
Inspect trunk for rust (especially below any panels)
Jack, wheel wrench, tool kit all present?
Evaluation Procedure (add up points scored)
22-28!! =! Excellent
15-21!! =! Good
8-14! ! =! Average
0-7! ! = ! Poor