4B 1 FIAT PUNTO 1998 176 / 1.G Workshop Manual

7B*6 Automatic transmission
Gear selector cable -adjustment
1 Remove the battery and tray as described In Chapter 5A for access to the transmission. 2 Disconnect the selector cable from the lever on Ihe transmission. 3 Move the selector fever inside the vehicle to the N (Neutral) position, then move the lever on the transmission to Its central (Neutral) position. Locate the cable end over the lever. If the cable end fitting does not line up exactly with the hole In Ihe lever, loosen the adjustment nut and reposition the end fitting. 4 With the adjustment correct reconnect tha cable to the lever, then move the selector lever to the P (Park) position. Check that the lever on the transmission has also moved to the P position. 6 Refit the battery and tray as described in Chapter 5A. 6 Road test the vehicle, and check for correct operation in all selector lever positions.
9 Gear selector cable -removal and refitting at
7 Inside the vehicle disconnect the selector cable from the bottom of the selector lever (hen remove it from the support bracket, a Withdraw the cable into the engine compartment, and remove it.
Refitting 9 Refitting is a reversal of removal, but adjust the cable as described in Section 8. 10 Check that It is only possible to start the engine in positions P and N. Reposition the selector lever switch If necessary. 11 Road test the vehicle, and check for correct operation In ell selector lever positions.
10 Transmission oil pump - & mnvtiifll rAtiMlitA removal a/id refitting
Removal 1 Using an Allen key. unscrew the screw and remove the selector lever knob from the lever. 2 Remove the oddment tray and the ashtray. 3 Remove the screws and withdraw the centre console and selector mechanism cover. 4 Unscrew the mounting screws, slightly lift the centre console, then disconnect the wiring and remove the console, 5 Remove the battery and tray as described in Chapter 5A for access to the transmission, 6 Disconnect the selector cable from the lever on the transmission.
Removal 1 Apply the handbrake, then lack up the front of the vehicle and support on axle stands (see Jacking and vehicle support). Remove the left-hand wheel. 2 Unscrew the screws and remove the wheel arch liner. 3 Working through the left-hand wheel arch, remove Ihe three bolts which secure the oil pump. 4 Attach a slide hammer to the oil pump, using the two tapped holes provided. Withdraw the pump using the slide hammer. Be prepared for some oil spillage. Recover the gasket end O-ring (see illustrations). 5 If the pump is defective, it must be renewed; no spares are available.
Refitting 6 Before refitting Ihe oil pump, clean Ihe mating surfaces of the transmission and pump. 7 Rt the oil pump, U9ing a new gasket and a new O-ring. Secure the pump with the three bolts.
8 Refit the wheel arch liner, then refit tto wheel and lower the vehicle to the ground. 9 Check the transmission fluid level » described earlier in this Section, and top-upif necessary.
11 Accelerator pedal & mfcro-Bwftcb(es) -checking
and
adjustment ^
1 Correct adjustment of the micro-awtlch which senses the accelerator pedal position s essential for correct operation of the clutch.
A
quick check can be made by listening for the switch clicking as the accelerator a depressed. For an accurate check, proceed as follows. 2 Disconnect Ihe mlcroswitch wiring connector (nside the vehicle. Connect a continuity tester across the terminals of the switch, located at the top of (he pedal box (see Illustration}. 3 Remove the air cleaner and air ducting as described in Chapter 4A. 4 With the accelerator pedal releassd, th« switch must be closed (zero resistance). Slowty depress the pedal, and check that the switch opens when the throttle valve on the throttle housing is 30° open. This will occur when the pedal has travelled between 3 and 7 mm. Adjust the switch position if necessary. 5 If the switch is permanently open or permanently closed, and adjustment makes no difference, renew ft. 6 Remake the original wiring connections on completion,
12 Automatic transmission -overhaul
Apart from the operations described earlier in this Section, transmission overhaul should be entrusted to a Rat dealer or transmission specialist.
10.4a Using a slide hammer to remove the oil pump from the transmission 10.4b Automatic transmission oil pump O-dng (1), housing (2) and gasket (3) 11.2 Continuity tester connected ecross the accelerator pedal micro-switch

6*172

Chapter 8
Driveshafts
Contents
Oriveshaft gaiter check See Chapter 1A or 1B General information 1 Oriveshaft overhaul and rubber gaiter renewal 3 intermediate driveshaft - removal and refitting 4 Driveshafts - removal and refitting 2
Degrees of difficulty

Easy,
suitable for ^ novtoewithittle experience ^
Fatly
easy,
suitable for beginner with
some experience
^

Fairty
difficult, suitable
tor
competent OtYmechanlc

Difficult,
suitable for experienced DIY mechanic ^
Veiydfficult, ^
suitable
for
expert DIY
or professional ^
Specifications
General Type
Lubrication lubricant type
Torque wrench settings Driveshaft nut* All models except turbo diesel (M22 plain) Turbo diesel (M24 with staking and captive washer) Roadwheel bolts Suspension strut-to-hub carrier bolts Track-rod balljolnt-to-hub carrier 'Use a new nut.
Unequal-length, solid steel shafts, splined to Inner and outer constant velocity joints. Intermediate shaft with support bearing on turbo diesel models with equal length driveshafts.
Fiat specification grease, supplied with gaiter repair kit
Nm Ibfft
240 177 280 207 85 63 70 52 40 30
1 General information
Power is transmitted from the differential to
Ihe
roadwheels by the driveshafts. via inboard and outboard constant velocity (CV) joints (we illustrations). An intermediate drive shaft, with its own support bearing is fitted between the gearbox output and right-hand drive shafts on turbo desei models (see Illustration overleaf). This layout has the effect of equalising driveshaft angles at sll suspension positions and reduces tfveshaft flexing, which improves directional stability, particularly under acceleration. The outer Rzeppa type CV joints allow smooth transmission of drive to the wheels at all steering and suspension angles. Drive Is transmitted by means of a number of radially static steel balls that run In grooves between
the two halves of the joint. The type of inboard CV joint fitted is model dependant. Those fitted to all except the turbo diesel models are of the plunge-cup type; drive is transmitted across the joint by means of three rollers, mounted on the driveshaft in a tripod arrangement, that are radially static but are free to slide in the grooved plunge cup.
The inboard CV joints fitted to turbo diesel models are of the Rzeppa type, similar to those at the outboard end of the driveshaft. On the right-hand driveshafl, the joint is bolted directly to the end of the intermediate driveshaft flange. On the left-hand driveshaft, the joint is bolted to the transmission output shaft flange.
1.1a Cross section of driveshaft - petrol and non-turbo diesel models A Transmission side B Roadwheef side

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).

A


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.

Driveshafts 8*5
4.4 Unbolt the Intermediate shaft from the 4.5a Withdraw the intermediate shaft from support bracket the transmission 4.5b Recover the dust seal
4 Unbolt the intermediate shaft from the support bracket (see Illustration). 5 Attach a slide hammer to the intermediate shaft flange and draw the splined end of the shaft out of the transmission. Take care to avoid damaging the oil seal. Recover the dust seal (see illustrations).
Refitting 6 Before installing the driveshaft, examine the oil seal in the transmission for signs of
damage or deterioration and, if necessary, renew it (it is advisable to renew the seal as a matter of course). 7 Thoroughly- clean the intermediate shaft splines and the aperture In the transmission. Fit a new dust seal to the shaft, then apply a thin film of grease to the oil seal lips, and to the intermediate shaft splines and shoulders. 8 Push the shaft squarely into the trans-mission, taking care to avoid damaging the oil
9 Line up the intermediate shaft bearing with the suppori bracket, then insert the bolls and tighten them securely. 10 Refit the right-hand driveshaft as described in Section 2, then refit the road-wheel and lower the vehicle to the ground. Tighten the roadwheel bolts to the specified torque. 11 On completion refill the transmission with the specified quantity and grade of oil. as described in Chapter 1B.
8

9«1
Chapter 9
Braking system
Contents
Brake disc - inspection, removal and refitting 4 Brake fluid level check See Weekly checks Brake fluid renewal See Chapter 1A or 1B Brake warning lamp check See Chapter 1A or 1B Front brake caliper - removal, overhaul and refitting 3 Front brake pad check See Chapter 1A or 1B Front brake pads - renewal 2 General information 1 Handbrake - checking and adjustment 9
Handbrake cables - removal and refitting 10 Hydraulic pipes end hoses - renewal 13 Hydraulic system - bleeding 11 Master cylinder - removal and refitting 12 Roar brake shoe check See Chapter 1A or 1B Rear brake shoes - renewal 5 Rear brake drums - removal, inspection and refitting 6 Rear wheel cylinder - removal, overhaul and refitting 7 Stop-light switch - adjustment, removal and refitting 6
Degrees of difficulty

Easy, suitable
far
novice with Sttle
experience ^
Fairly
easy,
suitable ^ (orbeginnerwith ®
some
experience
Fairly difficult, suitable
for
compe«ent ^ CHYmechanlc ^

Difficult, suitable for
experienced DIY « mechanic ^
Very difficult, ^
suitable
for
expert DIY
or professional ^
Specifications
Front disc brakes Type Disc with single-piston sliding calipers Disc diameter Petrol models with single-point Injection 240.0 mm Petrol models with multi-point Injection 257.0 mm Non-turbo diesel models 240.0 mm Turbodieselmodels 257.0 mm Disc thickness (new); Petrol models with single-point injection 10.80 to 11.10 mm Petrol models with multi-point Injection 11.80 to 12.10 mm Non-turbo diesel models 10.80 to 11.10 mm Turbodieselmodels 11.80 to 12.10 mm Minimum disc thickness (wear limit): Petrol models with single-pant Injection 9.20 mm Petrol models with multi-point Injection 10.20 mm Non-turbo diesel models 9.20 mm Turbo diesel models 10.20 mm Maximum disc runout 0.15 mm Brake pad friction material minimum thickness 1.5 mm
Rear drum brakes Drum Inner diameter (new) 180.0 to 180.25 mm Maximum drum diameter (wear limit) 181.35 mm Minimum brake shoe lining thickness 2.0 mm
Torque wrench settings Nm ibf ft
Bfeed
screw 6 4 Brake disc locating studs 12 9 Brake drum locating studs 12 9 Brake pipe and hose unions 14 10 Front caliper mounting bracket-to-hub carrier bolts 53 39 Front caliper-to-caliper bracket guide pin bolts 12 9 fleer wheel cylinder mounting boils 10 7 Roadwheel bolts 85 63

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

9*4 Braking system
3.5 Unscrew the caliper upper guide pin bolt and remove tho caliper body (torn the bracket
3 Front brake caliper -removal, overhaul and refitting ^

A


Warning: Before starting work, refer to the warnings at the beginning of Sections 2 and 11 concerning the dangers of handling asbestos dust and hydraulic fluid.
Removal 1 Chock the rear wheels, apply the handbrake, then |ack up the front of the vehicle and support it on axle stands {see Jacking and vehicle support). Remove the appropriate front roadwheel. 2 Remove the brake pads as described In Section 2. 3 To minimise fluid loss dunng the following operations, remove the master cylinder reservoir cap. then
tig hi en
it down onto a piece of polythene, to obtain an airtight seat. Alternatively, use a brake hose clamp to seal off the flexible hose running to the caliper.

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Warning: Do not use an ordinary G-clamp or mole grips for this purpose, as these can easily damage the hydraulic hose Internally, possibly leading to failure. 4 Clean the area surrounding the brake hose union, then slacken ft using a ring spanner. It won't be possible to separate the union completely without twisting the hose ai this slage.
3.7 Unscrew the two securing bolts (arrowed) and remove the caliper mounting bracket from the hub carrier
5 On petrol models without ABS, unscrew the caliper upper guide pin bolt using a hex bit or Allen key and remove the caliper body from the bracket (see illustration). 6 Hold the brake hose and rotate the caliper to unscrew the hose union from the caliper body. Cover the open ends of the union and the caliper fluid inlet, to prevent dirt Ingress. Alternatively, Ihe flexible brake hose may be separated from the rigid brake pipe, at the bracket mounted on the Inner wheel arch. 7 If desired, the caliper mounting bracket can be removed from the hub carrier after unscrewing ihe two securing bolts (see Illustration) but note that locking compound must be applied to the bolt threads on refitting.
Overhaul Note: Before commencing work, ensure that the appropriate caliper overhaul kit
Ss
obtained. 8 With the caliper on the bench, wipe away all (races of dust and dirt, but avoid inhaling the dust, as It
Is
a health hazard. 9 Place a small block of wood between the caliper body and tho piston, to act as padding. Remove the piston by applying a Jet of low pressure compressed air (such as that pioduced by a tyre foot pump) to the fluid inlel port.

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Warning: Protect your hands and eyes when using compressed air In this manner • brake fluid moy be ejected under pressure when the pisfon pops out of Its bore. 10 Peel the dusi seal from the piston, then use a soft, blunt instrument (ie not a screwdriver) to extract the piston seal from the caliper bore. 11 Thoroughly clean all components, U9tng only methylated spint or clean hydraulic fluid, Never use mineral-based solvents such as petrol or paraffin, which will attack Ihe hydraulic system rubber components. 12 The caliper piston seal, the dust seal and the bleed nipple dust cap, a/e oniy available as part of a seat kit. Since the manufacturers recommend that the piston seal and dust seal are renewed whenever they are disturbed, all of these components should be discarded on disassembly and new ones fitted on reassembly as a matter of course. 13 Carefully examine all parts of the caliper assembly, looking for signs of wear or damage. In particular, the cylinder bore and piston must be free from any signs of scratches, corrosion or wear. If there is any doubt about ihe condition of any part of the caliper, the relevant port should be renewed Note that the piston surface is plated, and must not be polished with emery or similar abrasives to remove corrosion or scratches. In addition, the pistons are matched to the caliper bores and can only be renewed as a part of a complete caliper assembly. 14 Check that the threads in the caliper body and the mounting bracket are in good condition, Check that both guide pins are
undamaged, and (when cleaned) a reasons^' tight sliding fit In the mounting bracket bores. 15 UsecompressedairtOblow clear the IkuJ passages. Warning: Wear eye protection when using compressed
air.
16 Before commencing reassembly, en$vr« that all components are spotlessly-clean
and
dry. 17 Soak the new piston seal m clean hydraulic fluid, and fit it to the groove
In
tftt cylinder bore, using your fingers only (rift tools) to manipulate it into place. 18 Fit the new dust seal inner ftp to tne cylinder groove, smear clean hydraulic Hud over the piston and caliper cylinder
bore, and
twist ihe pfaton into the dust seal. Press tne piston squarely Into the cylinder, then sildt the dust seal outer lip to tho groove in we piston
Refitting 19 Where applicable, refit the caliper mounting bracket to thB hub earner. Ccaitto threads ol the mounting bolts with locking compound, then tighten them to the speclfed torque. 20 Hold the brake hose and rotate Ihe calip* to screw the hose union back Into the caliper body. 21 On petrol models without ABS, place the caliper In position on the bracket and tighter the caliper upper guide pin bolt to the specified torque. 22 Relit ihe brake pads as described m Section 2. 23 On all models, tighten the brake hose-to-callper union securely. 24 Check that the caliper slides smoothly
on
its guide pins. 25 Where applicable, remove the polytbste from the master oyhnder rasarvoir cap, or remove tho clomp from the fluid hose, ai applicable. 26 Bleed tho hydraulic fluid circuit as desenbed m Section 11. Note that if rootMf part of the system has been disturbed, < should only be necessary to bleed tha relevant front circuit, 27 Depress the brake pedal repeatedly to bring ihe pads into contact with ihe brake disc, and ensure that normal pedal
pressure is
restored. 28 Refit the roadwheel, and lower tha veti'cfc lo ihe ground.
4 Brake disc -
inspection,
removal
and
refitting
Inspection 1 Firmly apply the handbrake, then jaefcup the front of the car and support It securely
oft
axle stands (see Jacking and vehicle
support1,.
Remove the front roadwhesls.
expert22 f
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