Chapter 1 Routine maintenance and servicing

1595 Ford Fiesta RemakeJJump start Starting the engine of a vehiclewith a discharged or weak battery byattaching jump leads from the weak battery toa charged or helper battery.LLoad Sensing Proportioning Valve (LSPV) Abrake hydraulic system control valve thatworks like a proportioning valve, but alsotakes into consideration the amount of weightcarried by the rear axle.Locknut A nut used to lock an adjustmentnut, or other threaded component, in place.For example, a locknut is employed to keepthe adjusting nut on the rocker arm inposition.Lockwasher A form of washer designed toprevent an attaching nut from working loose.MMacPherson strut A type of frontsuspension system devised by EarleMacPherson at Ford of England. In its originalform, a simple lateral link with the anti-roll barcreates the lower control arm. A long strut - anintegral coil spring and shock absorber - ismounted between the body and the steeringknuckle. Many modern so-called MacPhersonstrut systems use a conventional lower A-armand don’t rely on the anti-roll bar for location.Multimeter An electrical test instrument withthe capability to measure voltage, current andresistance.NNOx Oxides of Nitrogen. A common toxicpollutant emitted by petrol and diesel enginesat higher temperatures.Glossary of technical terms REF•25Overhead cam (ohc) engine An engine withthe camshaft(s) located on top of the cylinderhead(s).Overhead valve (ohv) engine An engine withthe valves located in the cylinder head, butwith the camshaft located in the engine block.Oxygen sensor A device installed in theengine exhaust manifold, which senses theoxygen content in the exhaust and convertsthis information into an electric current. Alsocalled a Lambda sensor.PPhillips screw A type of screw head having across instead of a slot for a correspondingtype of screwdriver.Plastigage A thin strip of plastic thread,available in different sizes, used for measuringclearances. For example, a strip of Plastigageis laid across a bearing journal. The parts areassembled and dismantled; the width of thecrushed strip indicates the clearance betweenjournal and bearing.PlastigagePropeller shaft The long hollow tube withuniversal joints at both ends that carriespower from the transmission to the differentialon front-engined rear wheel drive vehicles.Proportioning valve A hydraulic controlvalve which limits the amount of pressure tothe rear brakes during panic stops to preventwheel lock-up.the ozone in the upper atmosphere.Rocker arm A lever arm that rocks on a shaftor pivots on a stud. In an overhead valveengine, the rocker arm converts the upwardmovement of the pushrod into a downwardmovement to open a valve.Rotor In a distributor, the rotating deviceinside the cap that connects the centreelectrode and the outer terminals as it turns,distributing the high voltage from the coilsecondary winding to the proper spark plug.Also, that part of an alternator which rotatesinside the stator. Also, the rotating assemblyof a turbocharger, including the compressorwheel, shaft and turbine wheel.Runout The amount of wobble (in-and-outmovement) of a gear or wheel as it’s rotated.The amount a shaft rotates “out-of-true.” Theout-of-round condition of a rotating part.SSealant A liquid or paste used to preventleakage at a joint. Sometimes used inconjunction with a gasket.Sealed beam lamp An older headlight designwhich integrates the reflector, lens andfilaments into a hermetically-sealed one-pieceunit. When a filament burns out or the lenscracks, the entire unit is simply replaced.Serpentine drivebelt A single, long, wideaccessory drivebelt that’s used on somenewer vehicles to drive all the accessories,instead of a series of smaller, shorter belts.Serpentine drivebelts are usually tensioned byan automatic tensioner.OOhm The unit of electrical resistance. Onevolt applied to a resistance of one ohm willproduce a current of one amp.Ohmmeter An instrument for measuringelectrical resistance.O-ring A type of sealing ring made of aspecial rubber-like material; in use, the O-ringis compressed into a groove to provide thesealing action.O-ringRRack-and-pinion steering A steering systemwith a pinion gear on the end of the steeringshaft that mates with a rack (think of a gearedwheel opened up and laid flat). When thesteering wheel is turned, the pinion turns,moving the rack to the left or right. Thismovement is transmitted through the trackrods to the steering arms at the wheels.Radiator A liquid-to-air heat transfer devicedesigned to reduce the temperature of thecoolant in an internal combustion enginecooling system.Refrigerant Any substance used as a heattransfer agent in an air-conditioning system.R-12 has been the principle refrigerant formany years; recently, however, manufacturershave begun using R-134a, a non-CFCsubstance that is considered less harmful toSerpentine drivebeltShim Thin spacer, commonly used to adjustthe clearance or relative positions betweentwo parts. For example, shims inserted into orunder bucket tappets control valveclearances. Clearance is adjusted bychanging the thickness of the shim.Slide hammer A special puller that screwsinto or hooks onto a component such as ashaft or bearing; a heavy sliding handle on theshaft bottoms against the end of the shaft toknock the component free.Sprocket A tooth or projection on theperiphery of a wheel, shaped to engage with achain or drivebelt. Commonly used to refer tothe sprocket wheel itself.Starter inhibitor switch On vehicles with anREF