Toyota Landcruiser Rear Brake Upgrade Package - Hoppers Stoppers
Toyota Landcruiser Rear Brake Upgrade Package - Hoppers Stoppers
Toyota Landcruiser Rear Brake Upgrade Package - Hoppers Stoppers
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HOPPERS HOPPERS STOPPERS<br />
STOPPERS<br />
May 2007<br />
<strong>Toyota</strong> <strong>Landcruiser</strong><br />
<strong>Rear</strong> <strong>Brake</strong> <strong>Upgrade</strong><br />
<strong>Package</strong><br />
9 Nevada Ct<br />
<strong>Hoppers</strong> Crossing Vic 3029<br />
Ph 03 97486950<br />
Fax 03 97485965<br />
Email hopstop@hoppers.com.au<br />
Web www.hoppers.com.au
<strong>Toyota</strong> <strong>Landcruiser</strong> <strong>Rear</strong> <strong>Brake</strong> <strong>Upgrade</strong> <strong>Package</strong><br />
HOPPERS HOPPERS STOPPERS<br />
STOPPERS<br />
THE INFORMATION CONTAINED<br />
WITHIN THIS DOCUMENT IS<br />
PROPRIETY CONFIDENTIAL<br />
AND MUST NOT BE DIVULGED<br />
TO ANY THIRD PARTY WITHOUT<br />
OUR WRITTEN CONSENT<br />
2
<strong>Toyota</strong> <strong>Landcruiser</strong> <strong>Rear</strong> <strong>Brake</strong> <strong>Upgrade</strong> <strong>Package</strong><br />
<strong>Rear</strong> <strong>Brake</strong><br />
<strong>Upgrade</strong><br />
<strong>Package</strong><br />
78/79 Series<br />
<strong>Toyota</strong><br />
<strong>Landcruiser</strong><br />
Original rear slip-on disc with small<br />
caliper<br />
Handbrake inside rear disc<br />
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Introduction<br />
<strong>Toyota</strong> <strong>Landcruiser</strong> 78/79 Series Vehicles are used extensively<br />
throughout the country, and in particular, are favoured by mining<br />
operators, many in underground use where conditions are<br />
extreme.<br />
Whilst the basic vehicle is well respected by the industry, the rear<br />
disc brake arrangement has proven to be inadequate for the<br />
conditions, with the rear brake pads and hand brake both<br />
exhibiting accelerated wear way beyond the rest of the vehicle.<br />
In worst conditions, the rear brake linings will wear to the metal<br />
backing plates in a matter of weeks, resulting in total loss of rear<br />
brakes with accompanying work safety concerns. Handbrakes<br />
often fail to hold with days.<br />
Analysis of the Problem<br />
With this series of 78/79 series vehicles, <strong>Toyota</strong> moved to a rear<br />
disc brake design incorporating a drum type hand brake within the<br />
disc.<br />
There may have been reasons for this design, but it seems to<br />
have been a retrograde step when subjected to regular immersion<br />
in muddy and highly corrosive environments.<br />
There seem to have been several compromises needed to arrive<br />
at this design.<br />
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<strong>Toyota</strong> <strong>Landcruiser</strong> <strong>Rear</strong> <strong>Brake</strong> <strong>Upgrade</strong> <strong>Package</strong><br />
Cause of <strong>Rear</strong> <strong>Brake</strong> Problems<br />
1 Combining a drum handbrake and a disc rotor and caliper<br />
within the confines of a 16-inch wheel necessitates a<br />
small brake caliper and small pad radial section, resulting<br />
in an undersized pad area.<br />
The standard design has a thin disc and a handbrake of<br />
small diameter and swept area relative to the weight of<br />
the vehicle.<br />
2 The backing plate and handbrake arrangement allow mud<br />
and slurry to enter but not exit, causing abrasives to<br />
accumulate and rapidly destroy the handbrake, including<br />
its function as an emergency brake.<br />
3 The small disc pad contact area is at odds with the<br />
affects of loading under abrasive conditions where rates<br />
of wear are parabolic for wear rate versus load.<br />
4 The handbrake design is fiddly and complicated with<br />
many small parts that prove to be difficult to assemble<br />
correctly.<br />
<strong>Hoppers</strong> <strong>Stoppers</strong> design solution<br />
There appear to be a few possible ways to approach this<br />
problem, with a couple of companies proposing designs.<br />
Some take unconventional and unusual approaches but appear<br />
expensive to purchase and repair; with their application probably<br />
only justified if they perform perfectly for a very long time.<br />
<strong>Hoppers</strong> <strong>Stoppers</strong>' approach is to stick to proven principles and<br />
overcome the basic weakness of the existing design.<br />
By all reports, the front brakes on these <strong>Toyota</strong>s work adequately,<br />
and considering their environment do not give significant<br />
problems in the field.<br />
In our view these brakes are not particularly special in their<br />
engineering, just the same basic front brakes that they have<br />
made for many years.<br />
If we built a rear brake set as solid and even better designed than<br />
the front it should last as long. This requires a big, thick disc rotor<br />
and brake lining swept area similar to the front.<br />
HOPPERS HOPPERS STOPPERS<br />
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<strong>Rear</strong> <strong>Brake</strong><br />
<strong>Upgrade</strong><br />
<strong>Package</strong><br />
78/79 Series<br />
<strong>Toyota</strong><br />
<strong>Landcruiser</strong><br />
300 dia by 28 thick rotor fitted to<br />
original hub<br />
Larger revised caliper<br />
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<strong>Toyota</strong> <strong>Landcruiser</strong> <strong>Rear</strong> <strong>Brake</strong> <strong>Upgrade</strong> <strong>Package</strong><br />
<strong>Rear</strong> view of transfer case<br />
Disc type handbrake installed<br />
1 Rotors<br />
Being a full floating rear hub and axle design, restricts the<br />
inside diameter of the rotor face, particularly when we try to<br />
retain the simple loose fit "slip on" design.<br />
In order to achieve a suitably larger swept area, it is therefore<br />
better to attach the rotor from the inside in the same manner as<br />
the front arrangement.<br />
This will require the hub to be removed from the axle housing<br />
for disc fitment; this is not a big job and in any case allows<br />
repacking of the bearings.<br />
In order to facilitate the original conversion, 5 counter sunk<br />
holes need to be drilled on the rear carrier hubs, either at the<br />
mine's workshop or as a change over supplied by <strong>Hoppers</strong><br />
<strong>Stoppers</strong>.<br />
The end result is a 300mm diameter rotor; 28mm thick<br />
compared to the original 18mm thick and almost double the<br />
swept area.<br />
No other alterations are required and all standard bearings and<br />
seals are retained, with the ability to convert back to the<br />
original design if desired, say at time of trading in the vehicle.<br />
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Improved Design By <strong>Hoppers</strong> <strong>Stoppers</strong> Handbrake<br />
Relocation<br />
In order to provide a suitably robust rear caliper and rotor design,<br />
it is therefore necessary to go back to the 'old days' and relocate<br />
the park brake back to the rear of the gearbox transfer case.<br />
As drum brakes accumulate abrasives, it is best to do this with a<br />
disc brake design, the disc being attached to the output flange<br />
and the caliper of simple mechanical lever type attached to the<br />
end of the transfer case.<br />
This allows us to utilize the differential ratio to "multiply" the brake<br />
effect for an effective park/emergency brake, which is also better<br />
located up higher for less emersion in mud.<br />
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<strong>Hoppers</strong><br />
<strong>Stoppers</strong><br />
<strong>Rear</strong> <strong>Brake</strong><br />
Design<br />
78/79 Series<br />
<strong>Toyota</strong><br />
<strong>Landcruiser</strong>
<strong>Toyota</strong> <strong>Landcruiser</strong> <strong>Rear</strong> <strong>Brake</strong> <strong>Upgrade</strong> <strong>Package</strong><br />
2 Caliper Design<br />
Within the automotive industry, all common rear calipers are<br />
much smaller than the front with usually much smaller pad<br />
area.<br />
<strong>Brake</strong> balance considerations dictate much smaller rear<br />
hydraulic piston areas, essentially meaning that there is no<br />
readily available alternative rear caliper that offers a solution.<br />
We therefore achieve our desired large pad area and thick<br />
rotor requirements by sleeving an Australian made front caliper<br />
down to smaller bore piston of suitable diameter.<br />
This also has an added benefit of allowing us to make the<br />
sleeves and pistons from corrosion resistant materials more<br />
suitable for the intended use.<br />
These calipers are plated cast iron, and by specification<br />
designed for regular immersion in dirt and water.<br />
3 <strong>Brake</strong> Pads<br />
As the base calipers are originally for the front of a locally<br />
made vehicle, the pads are available in many material options.<br />
<strong>Brake</strong> torque applied by a caliper to a rotor is proportional to<br />
the hydraulic area and does not change with pad area.<br />
It is therefore possible to reduce the specific load on the pad,<br />
greatly reduce wear rate and still have correct brake torque.<br />
4 Attachment<br />
Caliper mounting to the axle housing is via a 12mm thick steel<br />
plate attached to the original backing plate holes using original<br />
size 4 off 12mm bolts.<br />
For comparison, the original caliper attaches to a 5mm plate.<br />
The new caliper cradle attaches to this using 2 off 12mm bolts,<br />
which are the same size as original <strong>Toyota</strong> rear caliper usage.<br />
<strong>Rear</strong> <strong>Brake</strong> Kit ready for installation<br />
HOPPERS HOPPERS STOPPERS<br />
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Handbrake caliper, mounting<br />
bracket, disc rotor and carrier<br />
plate<br />
6<br />
<strong>Hoppers</strong><br />
<strong>Stoppers</strong><br />
<strong>Rear</strong> <strong>Brake</strong><br />
Design<br />
78/79 Series<br />
<strong>Toyota</strong><br />
<strong>Landcruiser</strong>
<strong>Toyota</strong> <strong>Landcruiser</strong> <strong>Rear</strong> <strong>Brake</strong> <strong>Upgrade</strong> <strong>Package</strong><br />
Before<br />
After<br />
Summary<br />
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5 Handbrake<br />
<strong>Hoppers</strong> <strong>Stoppers</strong> rear brake upgrade design principle is based<br />
on the fact that known acceptable front brake performance is<br />
repeatable at the rear.<br />
The basic vehicle remains unmodified in every aspect with<br />
existing brake master cylinder and piping, wheels, hubs, gearbox<br />
and such kept in standard condition.<br />
Fitting is simple and quick with normal tools and no special<br />
knowledge.<br />
Initial kits are not expensive and spare parts similar to that<br />
currently paid.<br />
The product is provided with an Engineers Report suitable for<br />
legal registration so that road going units can be converted and<br />
when sold, the new owner can legally continue to use the vehicle.<br />
To attach a suitable "tail shaft disc" we arrange a 10mm thick<br />
carrier plate to be sandwiched between the output flange and<br />
the universal joint yolk.<br />
This requires a small and acceptable movement of the slip joint<br />
at the front of the tail shaft.<br />
This caliper is designed for regular immersion in saltwater with<br />
all metal parts being either hot zinc coated or stainless steel.<br />
It is attached to the extension housing using six bolts already<br />
used to attach the end cover plate.<br />
The original hand brake cable is rerouted from its position on<br />
the left hand side of the axle to the chassis at the centre of the<br />
vehicle where it will work the centre-mounted handbrake.<br />
Note that we have avoided hydraulic actuation of the park<br />
brake as any brake fluid leaks would cause the brakes to<br />
release, as would any cooling of the hydraulics.<br />
Eg. After parking the vehicle with the brakes in a hot state.<br />
Handbrake<br />
From Inside<br />
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<strong>Toyota</strong> <strong>Landcruiser</strong> <strong>Rear</strong> <strong>Brake</strong> <strong>Upgrade</strong> <strong>Package</strong><br />
HOPPERS HOPPERS STOPPERS<br />
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<strong>Toyota</strong> <strong>Landcruiser</strong> <strong>Rear</strong> <strong>Brake</strong> <strong>Upgrade</strong> <strong>Package</strong><br />
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