1996 FIAT PUNTO ECO mode

6*1
Chapter 6
Clutch
Contents
Clutch - adjustment Clutch assembly - removal, inspection and refitting Clutch cable • removal and refitting Clutch hydraulic system - bleeding
Degrees of difficulty
2 Clutch master cylinder • removal and refitting 5 7 Clutch release mechanism - removal, Inspection and refitting 8 3 Clutch slave cylinder - removal and refitting 6 4 General information 1

Easy, suitable for
novice with little experience oi^

Faidy easy,
suitable for beginner
with
^
some
experience
Fairly difficult, suitable
for
competent ^
DIY
mechanic ^
Difficiit, suitable for ^ experienced DIY JR mechanic ^

V<*y difficult,
jk
suitable
for expert
DIY
« or professional ^
Specifications
General Type
Clutch pedal travel (cable-operated mechanism)
Friction plate diameter 8-valve petrol engines 16-valve petrol engines Diesel engines
Torque wrench setting Pressure plate retaining bolts
Single dry plate with diaphragm spring, cable- or hydraullcally-operated according to model 140.0 ± 5.0 mm
181.5 mm 190.0 mm 200.0 mm
Nm Ibf ft 16 12
1 General information
Vehicles with manual transmission are fitted with a pedal operated single dry plate clutch system. When the clutch pedal is depressed, effort is transmitted to the clutch release mechanism either mechanically by means of a cable, or hydraullcally by means of a master
2.5 Clutch cable adjustment
cylinder and slave cylinder. The release mechanism transfers effort to Ihe pressure plate diaphragm spring, which withdraws the pressure plate from the flywheel and releases the driven plate-Where applicable, the hydraulic fluid employed in the clutch system is the same as that used in the braking system, hence fluid is supplied to the master cylinder from a tapping on the brake fluid reservoir. The clutch hydraulic system must be sealed before work Is carried out on any of its components and then on completion, topped up and bled to remove any air bubbles.
2 Clutch - % adjustment §§ ^
Note: This procedure applies to models fitted with a cable-operated dutch
release
mechanism. No adjustment is possible on models with the hydrauHcaSy-operated system. 1 The clutch adjustment Is checked by measuring the clutch pedal travel. If a new cable has been fitted, settle it in position by depressing the clutch pedal at least thirty times. 2 Ensure that there are no obstructions
beneath the clutch pedal then measure the distance from the centre of the clutch pedal pad to the base of the steering wheel with the pedal In the at-rest position. Depress the clutch pedal fully to the floor, and measure the distance from the centre of the clutch pedal pad to the bata of the steering wheel. 3 Subtract the first measurement from the second to obtain the clutch pedal travel. If this is not with the range given in the Specifications at the start of this Chapter, adjust the clutch as follows. 4 The clutch cable Is adjusted by means of the adjuster nut on the transmission end of the cable. Access to the nut is from under the vehicle. Apply the handbrake then jack up the front of the vehicle and support on axle stands (see Jacking and vehicle support). 5 Working under the left-hand side of the engine compartment, slacken the locknut from the end of the clutch cable. Adjust the position of the adjuster nut. then depress the clutch pedal ten times and re-measure the dutch pedal travel. Repeat this procedure until the clutch pedal travel is as specified (see illustration). 6 Once the adjuster nut Is correctly positioned, and the pedal travel Is correctly set, securely tighten the cable locknut then lower the vehicle to the ground.

6*2 Clutch
3 Clutch cable -removal and refitting
Note: This procedure applies to models fitted with a cabfe-opemted dutch
release mechanism.
Removal 1 Remove the battery and tray as described In Chapter SA. If necessary, also remove the Inlet air ducting for Improved access as described In the relevant part of Chapter 4. 2 Unscrew the adjustment locknut and adjuster nut from the end of the cable fitting, (hen release the inner and outer cables from the transmission housing. Note the position of the damper biock. 3 Working Inside the vehicle, unhook the inner cable from the top of the clutch pedaL 4 Returning to the engine compartment, unscrew the nuts securing the outer cable to the bulkhead, then withdraw the cable assembly from the engine compartment. Refitting 5 Apply a smear of multi-purpose grease to the cable end fittings, then pass the cable through the bulkhead. Refit and tighten the nuts. 6 Inside the vehicle hook the inner cable onto the top of the clutch pedal. 7 in the engine compartment, attach the outer cable to the transmission housing and refit the damper block and nuts lo Ihe inner cable end. fi Adjust the cable as described in Section 2. 9 Refit the air ducting and battery with reference to Chapters 4 and 5A
4 Clutch hydraulic system -
i
Note: This procedure applies to models fitted with the hydraulicalty-operated clutch release mechanism.

A


Warning: Hydraulic fluid Is poisonous; thoroughly wash off spllfs from bare skin without delay. Seek Immediate medical advice If any fluid is swallowed or gets into the eyes. Certain types of hydraulic fluid are Inflammable and may ignite when brought into contact with hot components; when servicing any hydraulic system, It is safest to assume that the fluid IS Inflammable, and to take precautions against the risk of fire as though ft were petrof that was being handled. Hydraulic fluid Is an effective paint stripper and will also attack many plastics. If spillage occurs onto painted bodywork or fittings, ft should be washed off Immediately, using copious quantities of fresh water. It Is also hygroscopic - It can absorb moisture from the air, which then renders it useless. Old fluid may have
suffered contamination, and should never be re-used. When topping-up or renewing tho fluid, always use tha recommended grade, and ensure that It comes from a new seated container. General information 1 Whenever the clutch hydraulic lines are disconnected for service or repair, a certain amount of air will enter the system. The presence of air In any hydraulic system will Introduce a degree of elasticity, and in the clutch system this will translate into poor pedal feel and reduced travel, leading to inefficient gear changes and even clutch system failure. For this reason, the hydraulic lines must be sealed using hose clamps before any work la carried out and then on completion, topped up and bled to remove any air bubbles. 2 To seal off Ihe hydraulic supply to tha clutch slave cylinder, fit a proprietary brake hose clamp to the flexible section of the hose located over the transmission and tighten it securely. It will be necessary to remove the battery and battery tray to access the hose. 3 The most effective way of bleeding the clutch hydraulic system is to use a pressure brake bleeding kit. These are readily available in motor accessories shops and are extremely effective: the following sub-section describes bleeding the clutch system using such a kit. The alternative method is to bleed the system by depressing tho clutch pedal • refer to Chapter 9. Section 11, for details of this method.
Bleeding 4 Remove the protective cap from Ihe bleed nipple on the slave cylinder. Access can be improved by removing the battery and tray with reference to Chapter 5A. 5 Fit a ring spanner over the bleed nipple head, but do not slacken it at this point. Connect a length of dear plastic hose over the nipple and insert the other end into a clean container. Pour hydraulic fluid into the container, such that the end of the hose is covered. 6 Following the manufacturer's instructions, pour hydraulic fluid into the bleeding kit vessel 7 Unscrew the vehicle's fluid reservoir cap, then connect Ihe bleeding kit fluid supply hose to the reservoir. 8 Connect the pressure hose to a supply of compressed air - a spare tyre is a convenient source. Caution: Check that the pressure In the tyre does not exceed the maximum supply pressure quoted by the kit manufacturer, let soma sir escape to reduce the pressure, if necessary. Gently open the air valve and allow the air and fluid pressures to equalise. Check that there ere no teaks before proceeding. 9 Using the spanner, slacken the bleed pipe nipple until fluid and air bubbles can be seen to flow through the tube, into the container.
Maintain a steady flow until the emerging fluid la free of air bubbles; keep a watchful eye on the level of fluid in the bleeding kit vessel and the vehicle's fluid reservoir • if it Is allowed to drop too low, air may be forced into the system, defeating the object of the exercise. To refill the vessel, turn off the compressed air supply, remove the lid and pour In en appropriate quantity of clean fluid from a new container - do not re-use the fluid collected in the receiving container. Repeat as necessary until the ejected fluid is bubble-free. 10 On completion, pump the olutch pedal several times to assess its feel and travel. If firm, constant pedal resistance is not felt throughout the pedal stroke, it i6 probable that air Is still present in the system - repeat the bleeding procedure untii the pedal feel is restored. 11 Depressurise the bleeding kit and remove it from the vehicle. At this point, the fluid reservoir may be over-full; the excess should be removed using a clean pipette to reduce the level to the MAX mark. 12 Tighten the bleed pipe nipple using the spanner and remove the receiving container. Refit the protective cap. 13 On completion, assess the feel of the clutch pedal; if it exhibits any sponginess or looseness, further bleeding may be required. 14 Where removed, refit the battery and tray. 15 Finally, road test the vehicle and check the operation of the clutch system whilst changing up and down through the gsar9. whilst pulling away from a standstill and from a hill start.
5 Clutch master cylinder - & removal
and
refitting 5 S Note: This procedure applies to models
fitted
with the hydraulically-operated dutch
release
mechanism. Note: Refer to the warning at Ihe beginning
of
Section 4 regarding the hazards of
working
with hydraulic fluid.
Removal 1 Disconnect the battery negative terminal (refer lo Disconnecting the battery in the Reference Section of this manual). 2 Remove the air cleaner and air ducting as described in the relevant Part of Chapter 4. 3 For improved access on petrol engine models, remove the alternator as described In Chapter 5A. 4 Fit a brake hose clamp to the hose between the hydraulic fluid reservoir and the clutch master cylinder. Alternatively syphon ail the fluid from the reservoir. 5 Disconnect the fluid supply hose at the master cylinder, then unscrew the union nut and disconnect the hydraulic pipe from the cylinder outlet. Be prepared for some fluid loss by placing some rags beneath the master cylinder.

Manual transmission 7A*3
3,8 Unscrew the nut and disconnect the gear selector rod from the lever on the transmission unscrew the locknut and adjusting nut from the end of the clutch cable and disconnect the cable from the transmission. Recover the damper block. On models with a hydraulically operated clutch, unscrew the mounting bolts, release the slave cylinder pushrod from the re&ase arm on the transmission, then position the cylinder to one side.
7 Unscrew and remove the reverse gear Inhibiting device from the transmission. Tie the cable to one side out of the way. 8 Unscrew the nut and disconnect the gear selector rod from the lever on the transmission (see illustration). 9 Pull out the clip then disconnect the gear engagement cable from the control lever and release the cable from the mounting bracket (see illustrations). 10 Unscrew and remove the two upper transmisslon-to-englne mounting bolts. Unscrew the single bolt securing the starter motor to the transmission. 11 Remove the air cleaner and air ducting with reference to Chapter 4A or 4B. This Is necessary In order to fit the engine hoist 12 On 5-speed transmissions, trace the wiring back from the electronic speedometer sensor and disconnect the connector located on the left-hand side of the engine (see illustration). 13 On 6-speed transmissions, unscrew the knurled nut and disconnect the speedometer cable from the top of the final drive housing. 14 Support the weight of the engine using a hoist attached to the engine lifting eyes, or alternatively use a trolley jack and block of wood beneath Ihe engine. 15 Unscrew the Lambda/oxygen sensor from the exhaust downpipe and position It In a safe place to prevent damage. 16 Unscrew the nuts securing the downpipe to the exhaust manifold, then lower It and support on an axle stand. Recover the gasket. 17 Unbolt the support bracket from the engine and transmission. Recover the spacer plate. 18 Unbolt and remove the transmission lower cover, 19 Unscrew the remaining starter motor mounting bolts and support tho starter motor to one side. 20 Loosen and remove the clips securing the left- and right-hand driveshaft gaiters to the transmission output shafts.
3.9a Remove the clip to release the gear engagement cable 21 Unscrew and remove the boils securing the left-hand swivel hub assembly to the front suspension strut, then separate the components and support the swivel hub on an axle stand. 22 Move the swivel hub assembly outwards and disconnect the inner end of the dnveshaft from the transmission output shaft. Support the shaft away from the transmission to prevent damage to the garters. 23 Working beneath the vehicle, unscrew the botts securing the rear engine mounting to the underbody then unscrew the bolts securing the mounting to the transmission and withdraw the mounting assembly from under the vehicle. 24 Unscrew the bolts securing the left-hand engine/transmission mounting to Ihe body then unscrew the bolts from the transmission and remove the mounting. 25 Support the woight of the transmission on a trolley jack then unscrew the remaining nut and bolt from the belihousing and pull the transmission away from the engine. Lower it and remove from under the vehicle. A Warning: Support the trans-mission to ensure that it remains steady on the jack head. Keep the transmission levet until the Input shaft Is fully withdrawn from the clutch friction plate. Refitting
26 Refitting is a reversal of the removal procedure, but note the following points. a) Apply a smear of high-melting-point grease to the clutch friction plate splines; take care to avoid contaminating the friction surfaces.
3.12 Electronic speedometer sensor fitted to 5-speed transmissions
3.9b Removing the gear engagement cable from the mounting bracket b) Tighten all bolts to Ihe specified torque. c) Fit new clips to secure the driveshaft gaiters to the transmission output shafts. d) Adjust the clutch cable (where applicable) as described In Chapter 6.
Diesel models
Removal 27 Seloct a solid, level surface to park the vehicle upon. Give yourself enough space to move around it easily. Apply the handbrake then jack up the front of tho vehicle and support on axlo stands (see Jacking and vehicle support). Remove both front wheels. 28 Unbolt the relay support then remove the batlery and mounting tray as described in Chapter 5A. 29 On models with a cable operated clutch, unscrew the locknut and adjusting nut from the end of the clutch cable and disconnect the cable from the transmission. Recover the damper block. On models with a hydraulically operated clutch, unscrew the mounting botts. release the slave cylinder pushrod from the release arm on the transmission, then position the cylinder to one side, 30 Unscrew the nut and disconnect the gear selector rod from the lever on the transmission. 31 Disconnect the gear engagement cable from the control lever then slide out the clip and release the cable from the mounting bracket. 32 Unbolt the electronic rev counter sensor from the upper rear of the belihousing and position it to one side (see illustration).
3.32 Electronic rev counter sensor located in the upper rear of the belihousing

8*2 Driveshafts
f Outboard CV joint 3 Driveshaft 6 Flange 2 Gaiter clip A Garter 6 Inboard CV ioint
1.2 Intermediate driveshaft • turbo diesel models 1 Bearing flange 3 Washer S Retaining plate 2 Bearing A Circllp
2.S Extracting the driveshaft from the hub (arrowed) from the CV joint at the carrier transmission
The joints are protected by rubber g&itcrs and are packed with grease, to orovktt permanent lubrication. If wear Is detected in the joint. It can be detached from lii» driveshaft and renewed. Normally, the CV joints do not require additional lubrication, unless they havo been overhauled or lfi» rubber gaiters have been damaged, allotting the greasa to become contaminated. Rater
to
Chapter 1A or 1B for guidance In checking the condition of the driveshaft gaiters. Bolh driveshafts are splined at their outer ends, to accept the wheel hubs, ond ate threaded so that the hubs can be fastened to the driveshafts by means of a large, staked nut.
2 Driveshafts -removal and refitting & ^
Note: A balljoint separator tool will b» required for this operation. A new drivestnf, nut and tmck-rod end nut should be used
on
refitting. In addition, new lower arm
baHj&ot
nuts should be used. Removal 1 Chock the rear wheels, apply the handbrake, then jack up the front of tha vehicle and support on axle stands (see Jacking and vehicle support). Remove th« appropriate roadwheel(6). 2 The front hub must be held stationary
m
order to loosen the driveshaft nut. Ideally, M hub should be held by a suitable tool bolted Into placo using two of the roadwheel nuts, Alternatively, havo an assistant firmly apply the brake pedal to prevent the hub from rotating. Using e socket and extension bar, slacken and remove the driveshaft nut. Recover the washer (where fitted).

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Warning: The nut Is extremely tight. Discard the nut - a new
one
must be used on refitting. 3 Remove the locking clip and extract the brake caliper hydraulic hose (and where applicable, the brake pad wear indicator cable) from the bracket on the base of the suspension strut. 4 With reference to Chapter 10, Section 3. unbolt the base of the suspension strut from Ihe top of the hub carrier. 5 Temporarily refit the driveshaft nut to the end of the driveshaft, to prevent damage to the driveshaft threads, then using a solt-faced mallet, carefully tap the driveshaft from the hub carrier (see illustration). If the shaft is a tight fit, a suitable hub puller can be used to force the end of the shaft from the hub. Support tha end of the driveshaft • do not allow the end o the driveshaft to hang down as this svill strain the joint components and gaiters. 6 Proceed as follows, according to which driveshaft is to be removed. All models except turbo diesels 7 Remove the driveshaft gaiter clip from the CV joint at the transmission (see Illustration)

Driveshafts 8*3
2.9 On turbo diesel models, unscrew the driveshaft Allen bolts (right-hand driveshaft shown) 2.13 Fitting a new driveshaft nut
then pull the driveshaft away from the plunge cup. Position a container underneath the joint to catch any grease that may escape fdnveshaft grease becomes liquid with use). 6 Remove the driveshaft from under the vehicle. Cover the open plunge cup on the vehicle to prevent the ingress of dirt: use a plastic bag secured with elastic bands. Turbo diesel models 9 Unscrew the six Allen bolts securing the inboard end of the driveshaft to the inter-mediate shaft flange (right hand driveshaft) or gearbox output shaft flange (left hand drive-shaft flange) (see Illustration). Recover tho reinforcement plates (where fitted). 10 Remove the driveshaft from under the vehicle. Cover the exposed flange at the gearbox/intermediate shaft, to prevent the ingress of dirt; use a plastic bag secured with elastic bands. 11 Loosely refit one of the strut lower mounting bolts, to support the hub carrier whilst the driveshaft is out of the vehicle.
Befitting 12 After removing the temporarily-fitted bolt torn the strut mounting, pivot the hub carrier away from the vehicle and push the splined end of the driveshaft Into the hub.
13 Fit a new driveshaft nut, but do not fully tighten it at this point (see illustration). 14 Support the driveshatt with one hand and push the hub carrier back towards the vehicle. All models except turbo diesels 15 Re-engage the tripod at the inboard end of the driveshaft with the plunge cup at the gearbox. Slide the gaiter into position over the joint and briefly lift the lip of the gaiter to expel any air trapped inside. Ensure that the gaiter is seated squarely over the universal joint, then fit a new clip around the centre of the joint to secure it in place. Turbo diesel models 16 Align the inboard end of the driveshaft joint with the intermediate shaft flange. Refit the six driveshaft bolts and tighten them securely. All models 17 Refit the suspension strut-to-hub carrier bolts and tighten them to the correct torque * refer to Chapter 10 for details. 18 Refit the brake caliper hydraulic hose (and where applicable, the brake pad wear indicator cable) to the bracket on the base of the suspension strut. 19 Refit the roadwheel and bolts. 20 Lower the vehicle to the ground and tighten the driveshaft nut to the specified
torque. Stake the rim of the nut into the machined recess in the end of the driveshaft. using a hammer and punch (see illustrations). 21 Tighten the wheel bolts to the specified torque and refit the wheel trim/centre cap.
3 Driveshaft overhaul and rubber gaiter renewal
1 Remove the driveshaft from the vehicle as described In Section 2. 2 Unfasten the remainder of the rubber gaiter securing clips. Slide the gaiters towards the centre of the shaft, away from Ihe joints. Wipe off the majority of the old grease with a rag. Outboard CV joint - removal
All models except turbo diesels 3 Mark the relationship between the joint and the driveshaft using a scriber or a dab of paint. Using pair of circlip pliers, expand the circlip that holds the driveshaft m place and withdraw the shaft from the CV joint. Note that the circlip is captive in tho joint, and need not be removed, unless it appears damaged or worn (see illustration overleaf).
2.20a Tighten the driveshaft nut to the specified torque (roadwheel removed for clarity) 2.20b Stake the rim ot the nut Into the recess in the driveshaft 2.20c Recess machined into end of the driveshaft

I
8*4 Driveshafts
3.3 Using pair of circlip pliers, expand the circlip that holds the driveshaft in place
Turbo diesel models 4 Mark the relationship between the joint and the driveshaft using a scriber or a dab of paint. Attach a slide hammer to the dnveshaft nut thread. 5 Draw the joint off the driveshaft using the slide hammer, Use just enough effort to overcome the tension of the internal circlip.
Inboard CV joint removal All models except turbo dieseis 6 Al the inboard end of the driveshaft. use a hammer and centre punch to mark the relationship between Ihe shaft and |olnt. Remove the circlip with a pair of circlip pliers, then using a three-legged puller if required, draw Ihe tripod joint off the end of the driveshaft. Ensure that the legs of Ihe puller bear upon the cast centre section of the joint, not the roller beanngs (see illustration) Turbo diesel models 7 Al the inboard end of Ihe driveshaft. use a hammer and centre punch lo mark the relationship between the shaft and joint. Remove the circlip with a pair of circlip pliers, then carefully slide the CV joint from the end ot the shaft. Take great care to prevenl the
cage and bail bearings from falling out • secure the joint components together with wire or a nylon cable-tie. 8 Remove the washer then slide the flange from the end of the shaft.
Inspection 9 Slide both rubber gaiters off the driveshaft and discard them: It is recommended that new ones are fitted on reassembly as a matter of course. Recover the flexible washers (where fitted), making a note of their fitted positions, to aid correct refitting later. 10 Thoroughly clean the driveshaft splines, and CV joint components with paraffin or a suitable solvent, taking care not to destroy any alignment marks made during removal. 11 Examine Ihe CV joint components for wear and damage: in particular, check the balls and corresponding grooves for pitting and corrosion. If evidence of wear Is visible, then the joint must be renewed. Note that if the outboard CV joint Is to be renewed on turbo diesel models, it must be matched to the driveshaft using the colour-coded paint markings. 12 Where applicable, examine the tripod joint components for wear. Check thai the three rollers are free lo rotate without resistance and are not worn, damaged or corroded. The rollers are supported by arrays of needle bearings: wear or damage will show up as play In the rollers and/or roughness in rotation. If wear is discovered, the tnpod joint must be renewed. 13 Fit a new rubber gaiter (and where applicable, flexible washer) to the inboard end of the driveshaft and secure it In place on the shaft with a clip (see illustration).
Inboard CV joint - refitting
All models except turbo dieseis 14 Using Ihe alignment marks made during removal, fit the tripod joint onto the splines of the driveshaft. Tap It Into position using a soft faced mallet. To ensure that the tripod Joint rollers and driveshaft splines are not damaged, use a socket with an internal diameter slightly larger than I hat of the driveshafl as a drift. Refit the circlip. 15 Slide the gaiter over tho tripod joint and pack the gaiter with grease from the service kit.
3.6 Draw the tripod joint off the end of the driveshaft 3.13 FH s new rubber gaiter to the inboard end of the driveshaft and secure It in place with a clip
Caution: Do not allow grease to come
into
contact with vehicles paintwork, es discolouring may rasutt. Turbo diesel models 16 Slide the flange and washer onto the end of the shaft, then fit the joint Into position on the driveshaft splines, using the alignment marks made during removal. Fit the circlip. ' 17 Pack the gaiter with grease from His service kit, then slide the gaiter over the joint. Briefly lift the lip of the gaiter to expel ail the air from the joint, then secure the gaiter over the joint with a new clip. Caution: Do not allow grease to come
Into
contact with the vehicle's paintwork, as discolouring may result.
Outboard CV joint - refitting 18 Fit a new rubber gaiter to the outboard end of the driveshaft and secure it place with a dp, 19 Pack the CV joint with grease from Ihe service kit, pushing It into the ball grooves and expelling any air that may be trapped underneath. 20 Lubricate the splines of the drive shaft with a smear of grease, then whilst splaying the circlip open with a pair ot circlip pile*, insert the driveshaft into CV joint, observing the alignment marks made during removal. Note: On turbo diesel models, the circlip snaps into the CV Joint groove as Ifte driveshaft is inserted - no circlip pliers are required. Ensure that the circlip snaps securely Into place: pull on the shaft to check that it is held firmly In position. 21 Pack additional grease Into the joint to displace any air pockets, then slide the rubber gaiter over the joint. Briefly lift the lip ol the gaiter to expel all the air from Ihe joint, then secure it In place with a clip. 22 Refit the driveshaft (see Section 2).
4 Intermediate driveshaft - % removal and refitting J;
Note 1: This procedure applies only to turbo diesel engined models. Note 2: The intermediate shaft and
bearing
are not available as separate spares and cac only be renewed as a comptefe assembly.
Removal 1 Firmly apply the handbrake, then jack up the front of Ihe car and support It securely
on
axle stands (see Jacking and vehicle support). Remove the appropriate roadwheei(s). 2 Unbolt the inboard end of the right*hand driveshaft from the intermediate shaft
flange, as
described In Section 2. Suspend the dis-connected end of the driveshaft from a conven-ient point on the subframe, using wire or a cable-tie. to avoid straining the joint and gaiter. 3 Drain the oil from the transmission, with reference to Chapter 1B.

9*2 Braking system
2.3a Release tho locking clip ...
1 General information
The braking system is of the vacuum servo-assisted. dual-circuit hydraulic type. The arrangement of Ihe hydraulic system is such that each circuit operates one front ond ono rear brake from a tandem master cylinder. Under normal circumstances, both circuits operate In unison However, in the event of hydraulic failure in one circuit, lull braking force will still be available at two diagonally-opposite wheels. All models covered in this manual are fitted with front disc brakes and rear drum brakes. The front disc brakes are aotuated by single-piston sliding lype calipers, which ensure lhat equal pressure is applied to each brake pad. The rear drum brakes incorporate leading and trailing shoes, which are actuated by twin-piston wheel cylinders. A self-adjust mechanism is incorporated, to automatically compensate for brako shoe wear. As the brake shoe linings wear, the footbrnke operation automatically operates the adjuster mechanism, which effectively lengthens the shoe strut and repositions the brake shoes, to remove the llning-to-drum clearance. The mechanical handbrake linkage operates the brake shoos via a lever attached to the trailing brake shoe.
2.3b ... and remove the pad wear indicator wiring and brake fluid line from the suspension strut Load sensitive proportioning valves operate on the rear brake hydraulic circuits, to prevent the possibility of the rear wheels locking before the front wheels under heavy braking. Note: When servicing any part of the system, work carefully and methodically; also observe scmpulous cleanliness when overhauling any part of the hydraulic sysiem. Always renew components (in axle sets, where applicable) if In doubt about their condition, and use only genuine Fiat replacement parts, or at least those of known good quality. Note the warnings given in Safety first and at relevant points in this Chapter concerning fhe dangers of asoestos dust and hydraulic fluid.
Models with anti-lock braking system (ABS) Available as an option on certain models, the anti-lock braking system prevents skidding which not only optimises stopping distances but allows full steering control to be maintained under maximum braking. By electronically monitoring the speed of each roadwheel in relation to the other wneete, Ihe system can detect when a wheel is about to lock-up, before control is actually lost. The brake fluid pressure applied to that wheel's brake caliper is then decreased and restored (or modulated) several times a second until control
£s
regained. The system components comprise an Electronic Control Unit (ECU), four wheel speed sensors, a hydraulic unit, brake lines and dashboard mounted warning lamps.
The hydraulic unit incorporates a tandem master cylinder, a valve block which modulates the pressure in the brake hydrauli: circuits during ABS operation, an accumulator which provides a supply of highly pressursed brake fluid, a hydraulic pump to charge Ihe accumulator and an integral electronic control unit (ECU). The four wheel sensors are mounted on the wheel hubs. The ECU uses the signals produced by the sensors to calculate Ihe rotational speed of each wheel, The ECU has a self-diagnostic capability and will inhibit the operation of the ABS il a fault is detected, lighting the dashboard mounted warning lamp. The braking system will then revert lo conventional. non-ABS operation. II the nature of the laull ie not immediately obvious upon inspection, the vehicle must be taken to a Fiat dealer, who will have the diagnostic equipment
required
lo interrogate the ABS ECU electronically and pin-point the problem
2 Front brake pads - & renewal S

A


Warning: Renew BOTH sets ol front brake pads at the same
time
- NEVER renew the pads on
only
one wheel, as uneven braking may result

A


Warning: Note that the dust created by wear of the pads
may
contain asbestos, which is a health hazard. Never blow It out with compressed air, and don't inhale any of
it.
An approved filtering mask should be worn when working on the brakes. DO NOT use petrol or petroleum-based solvents to clean brake parts; use proprietary braks cleaner or methylated spirit only. 1 Firmly apply the handbrake, then jack up the front of the car and support it securely
on
axle stands (see Jacking and vehicle supporti. Remove the front roadwheeis. 2 Wording on one side of the vehicle, puth the caliper piston into its bore by pulling the caliper outwards. If necessary, press the piston back into its bore using a large G-clamp or a piston retraction tool. Keep a careful eye on the level of brake llufd in Ihe I reservoir as you do this - ensure that the
level
I does not rise above the MAX marking. 3 Whore applicable, release the locking dp and remove the pad wear indicator
wiring end
brake fluid line from the bracket at Ihe
base of
the suspension strut (see illustrations).
Petrol models without ABS 4 Remove the locking clip and exlracl the lower guide pin from the caliper (see illustrations) 5 Pivot the caliper body upwards and support In position with a length of wire or a cabie-fc. Avoid straining the hydraulic hose.
2,4a Remove the locking clip ... 2.4b ... and extract the lower guide pin from the caliper (petrol models without ABS)

Braking system 9®3
2.6a Unscrew the upper...
Petrol models with ABS and diesel models 6 Unscrew the upper and lower caliper guide cin bolts, using a slim open-ended spanner to counterhold the head of the guide pin (see illustrations). Discard the guide pin bolts -new items must be fitted on reassembly. 7 Lift the caliper from the hub/disc assembly (see illustration). Suspend it from a suitable point on the suspension using a length of wire or 8 cable-tie, to avoid straining the hydraulic hose.
All models Caution: Do not depress the brake pedal until the caliper is refitted, or the piston will
be
pushed out of Its bore. 8 Withdraw the brake pads from the caliper bracket (see illustrations). 9 Measure the thickness of each brake pad's foclion material. If either pad is worn at any point to the specified minimum thickness or less, all four pads must be renewed. Also, the pads should be renewed if any are fouled with oil or grease; there is no satisfactory way of degreasing friction material, once contaminated. If any of the brake pads are worn unevenly, or are fouled with oil or grease, trace and rectify the cause before reassembly.

A


Warning: Do not be tempted to swap brake pads over to compensate for uneven wear. 10 if the brake pads are still serviceable, carefully clean them using a clean, fine wire brush or similar and brake cleaning fluid. Pay particular attention to the sides and back of the metal backing. Where applicable, clean out the grooves in the friction material, and pick out any large embedded panicles of dirt
or
debris. 11 Clean the surfaces of the brake pad contact points In the caliper body and caliper mounting bracket. 12 Prior to fitting the pads, check that the giide pins can slide freely in the caliper body, and check that the rubber guide pin gaiters
are
undamaged. Brush the dust and din from
the
caliper and piston, but do not inhale it. as
4 may
contain asbestos. 13 Inspect the dust seal and the area around Ihe piston for signs of damage, corrosion or
models with ABS and diesel models)
brake fluid leaks. If evident, refer to Section 3 and overhaul the caliper assembly. 14 If new brake pads are to be fitted, the caliper piston must be pushed back into the cylinder, to allow for the extra depth of the friction material. Either use a G-clamp or similar tool, or use suitable pieces of wood as levers. Provided that the master cylinder reservoir has not oeen overfilled with hydraulic fluid, there should be no spillage, but keep a careful watch on the fluid level while retracting the piston. If the fluid level rises above the MAX level line at any time, the surplus should be siphoned off. A Warning: Do not syphon the fluid by mouth, as it is poisonous; use a syringe or an old poultry baster. 15 Apply a little high temperature brake grease to the contact surfaces of the pad backing plates: take great care not to allow any grease onto the pad friction linings. Similarly, apply brake grease to the pad contact points on the caliper bracket - again take care not to apply excess grease, which may contaminate the pads. 16 Place the brake pads in position on the caliper bracket, with the friction material facing the surfaces of the brake disc. Feed the wear indicator cable through the caliper body aperture.
Petrol models without ABS 17 Pivot the caliper body down over the brake pads, then refit the guide pin and clip.
2.7 Lift the caliper from the hub/disc assembly
Petrol models with ABS and diesel models 18 Fit the caliper body in position on the caliper bracket, then fit the new guide pin bolts and tighten them to the specified torque.
AH models 19 Check that the caliper body can slide freely on the guide pins. Ensure that the flexible hydraulic hose is not twisted or kinked In any way. Turn the steering from lock to lock and check that the hose does not chafe against the suspension or steering gear. 20 Where applicable, reconnect the pad wear indicator wiring and press it into the retaining clips on the suspension. 21 Repeat the above procedure on the remaining front caliper. 22 With both sets of front brake pads fitted, depress the brake pedal repeatedly until the pads are pressed into firm contact with the brake disc, and normal pedal pressure is restored. Any sponginess felt when depressing the pedal is most probably due to air trapped inside the hydraulic system - refer to Section 11 and bleed the braking system before progressing any further. 23 Refit the roadwheels. and lower the vehicle to the ground. 24 Check the hydraulic fluid level as described in Weekly checks. 25 Check the operation of the braking system thoroughly,
2.8a Withdraw the outboard... 2.8b ... and inboard brake pads from the caliper bracket