braking FIAT PUNTO 1994 176 / 1.G Owner's Manual

Braking system 9®11
Bleeding • using a one-way valve kit 21 As their name implies, these kits consist ol a length of tubing with a one-way valve Fitted, to prevent expelled air and fluid being drawn back into the system; some kits include a translucent container, which can be positioned so that the air bubbles can be more easily seen flowing from the end of the tube. 22 The kit is connected to the bleed screw, which is then opened. The user returns to the driver's seat, depresses the brake pedal with a smooth, steady stroke, and stowty releases it; this is repeated until the expelled fluid is clear of air bubbles. 23 Note that these kits simplify work so much that It is easy lo forget the master cylinder reservoir fluid level; ensure that this Is maintained at least above the MIN level line at all times.
Bleeding -using a pressure-bleeding kit 24 These kits are usually operated by the reservoir of pressurised air contained in the spare tyre. However, note that it will probably be necessary to reduce the pressure lo a lower level than normal; refer to the instructions supplied with the kit. 2$ By connecting a pressurised, fluid-filled container to the master cylinder reservoir, bleeding can be carried out simply by opening each screw In turn (in the specified sequence), and allowing the fluid to flow out until no more air bubbles can be seen in the expelled fluid. 28 This method has the advantage that the large reservoir of fluid provides an additional safeguard against air being drawn into the system during bleeding. 27 Pressure-bleeding is particularly effective when bleeding 'difficult' systems, or when bleeding the complete system at the time of routine fluid renewal.
All methods 28 When bleeding is complete, and firm pedal feel is restored, wash off any split fluid, lighten the bleed screws securely, and refit their dust caps (where applicable). 29 Check the hydraulic fluid level in the master cylinder reservoir, and top-up if necessary. 30 Discard any hydraulic fluid thai has been Wed from the system; it will not be fit for re-use. 91 Check the feel of the brake pedal. If it feels at all spongy, air must still be present in Vie system, and further bleeding is required. Failure to bleed satisfactorily after a reasonable repetition of the bleeding procedure may be due to worn master cylinder seals.
12 Master cylinder- % removal
and
refitting SK

A


Warning: 8efore starting work, refer to the warning at the beginning of Section 11 concerning the dangers of hydraulic fluid.
Removal 1 Remove the master cylinder fluid reservoir cap, and syphon the hydraulic fluid from the reservoir. Note: Do not syphon the fluid by mouth, as It Is poisonous; use a syringe or an old poultry baster. Alternatively, open any convenient bleed screw In the system, and gently pump the brake pedal to expel (he fluid through a tube connected to the screw (see Section 11). Disconnect the wiring connector from the brake fiuld level sender unit. 2 Carefully prise the fiuld reservoir from the seals and release it from the top of the master cylinder. 3 Wipe clean Ihe area around the brake pipe unions on the side of the master cylinder, and place absorbent rags beneath the pipe unions to catch any surplus fluid. Make a note of the correct fitted positions of the unions, then unscrew the union nuts and carefully withdraw the pipes. Plug or tape over the pipe ends and master cylinder orifices, to minimise the loss of brake fluid, and to prevent the entry of dirt into the system. Wash off any spilt fluid immediately with cold wafer.
A 22.45 to 22.65 mm
Cut the finger tips from an old rubber glove end secure them over the open ends of the brake pipes with elastic bands • this wifi heip to minimise fluid lots and prevent the Ingress of contaminants.
4 Slacken and remove the nuts securing the master cylinder to the vacuum servo unit, then withdraw the unit from the engine compartment. 5 Where applicable, recover the seals from the rear of the master cylinder, and discard them; new items must be used on refitting. 8 With the master cylinder removed, check that the distance between the end of the vacuum servo unit pushrod and the master cylinder mating surface is as shown in the diagram. If necessary, the distance may be adjusted by turning the nut at the end of the servo unit pushrod (see illustration).
Refitting 7 Fit new rubber seals and then press the fluid reservoir into the ports at the top of the master cylinder 8 Remove all traces of dirt from the master cylinder and servo unit mating surfaces, and where applicable, fit a new seal between the master cylinder body and the servo. 9 Fit the master cylinder to the servo unit, ensuring that the servo unit pushrod enters the master cylinder bore centrally. Refit the
B Adjustment nut

9*12 Braking system
master cylinder mounting nuts, and tighten them securely. 10 Wipe clean the brake pipe unions, then refit them to the correct master cylinder ports, as noted before removal, and lighten the union nuts securely. 11 Refill tha master cylinder reservoir with new fluid, and bleed the complete hydraulic system as described In Section 11. 12 Check the operation of the braking system thoroughly.
13 Hydraulic pipes and hoses - % renewal S§

A


Warning: Before starting work, refer to the warning at the beginning of Section 11 concerning the dangers of hydraulic fluid, 1 If any pipe or hose is to be renewed, minimise fluid loss by first removing the master cylinder reservoir cap. then tighten the cap down onto a piece of polythene to obtain
an airtight seal. Alternatively, flexible hoses can be sealed, If required, using a proprietary brake hose clamp; metal brake pipe unions can be plugged (if care Is taken not to allow dirt into the system) or capped immediately they are disconnected. Place a wad of rag under any union that is to be disconnected, to catch any spilt fluid-2 If a flexible hose Is to be disconnected, unscrew the brake pipe union nut before removing the spring clip which seeurea the hose to its mounting bracket. 3 To unscrew the union nuts, ll is preferable lo obtain a brake pipe spanner of the correct size; these are available from most large molor accessory shops. Failing this, a close-fitting open-ended spanner will be required, though if the nuts are tight or corroded, their flats may be rounded-off if the spanner slips. In such a case, a self-locking wrench is often the only way to unscrew a stubborn union, but It follows that Ihe pipe and the damaged nuts must be renewed on reassembly. Always clean a union and surrounding area before disconnecting it If disconnecting a compo-
nent with more than one union, make a carefJ note of the connections before disturbing
any
of them. 4 If a brake pipe Is to be renewed, it can b« obtained, cut to length and with the union nuts and end flares in place, from Fiat dealers. All that is then necessary is to bend It to shape, following the line of the original, baton fitting It to the vehicle. Alternatively, most motor accessory shops can make up bra Ha pipes from kits, bul this requires very carefii measurement of the original, to ensure (hat the replacement is of the correct length. Tha safest answer is usually to take the original lo the shop as a pattern. 5 On refitting, do not overtighten the union nuts. It is not necessary to exercise brute force to obtain a sound joint. 6 Ensure that the pipes and hoses an correctly routed, with no kinks, and that they are secured in the clips or brackets provided. After fitting, remove the polythene from lbs reservoir, and bleed the hydraulic system
88
described In Section 11. Wash off any split fluid, and check carefully for fluid leaks.

10*1
Chapter 12
Body electrical systems
Contents
Bulbs (exterior lights) - renewal 4 Bulbs (interior lights) - renewal 5 Electrical fault finding - general information 2 Exterior light units - removal and refitting 6 Fuses and relays - general Information 3 General information and precautions 1 Headlight beam alignment • general Information 6 Horn • removal and refitting 9 Instrument panel - removal and refitting 7 Loudspeakers - removal and refitting 10
Degrees of difficulty
Radio aerial - removal and refitting 11 Radio/cassette player • removal and refitting 12 Speedometer drive cable - removal and refitting 13 Switches - removal end refitting 14 Tailgate wiper motor - removal and refitting 15 Windscreen wiper motor - removal and refitting 17 Windscreen/tailgate washer system components • removal and refitting 16 Wiper arm • removal and refitting 18

Easy,
statable for ^
novice with liffle
|| experience ^
Fairly
easy,
suitable for beginner with ^ some experience ^
Fabtycffficiit,
suitable
for competent ^
DIY
mechanic ^

Difficult, suitable for
^ experienced DIY JR mechanic

Very difficult,
A,
suitable
for
expert DIY
Sj or professional ^
Specifications
Bulb ratings Watts Headlights 60/55 Front long range driving light 55 Front fogllght 55 Front direction Indicator light 21 Front sidelight 5 Front direction indicator repeater light 5 Stop light 21 Tall light 5 Rear direction indicator light 21 Reversing light 21 near fogllght 21 Hear number plate light 5 Courtesy light 10 Map reading light 5
1 Genera! information and precautions

A


Warning: fie/Ore carrying out any work on the electrical system, read through the precautions given in Safety first! at the beginning of this manual, and in Chapter 8. The electrical system is of 12-volt negative earth type. Power for the lights and all electrical accessories is supplied by a lead/acid type battery, which is charged by the alternator. This Chapter covers repair and service procedures for the various electrical components not associated with the engine. Information on the battery, alternator and starter motor can be found in Chapter 5. It should be noted that, prior to working on any component In the electrical system, the
battery negative terminal should first be disconnected, to prevent the possibility of electrical short-circuits and/or fires. Caution: Before proceeding, refer to Disconnecting the battery In the Reference Section of this manual for further information.
2 Electrical fault finding-general information
Note: Refer to the precautions given In Safety first! and in Section 1 of this Chapter before starting work. The following tests relate to testing ot the main electrical circuits, and should not be used to test delicate electronic circuits (such as antHock braking systems), particularly where an electronic con fro/ module is used.
General 1 A typical electrical circuit consists of an electrical component, any switches, relays, motors, fuses, fusible links or circuit breakers related to that component, and the wiring and connectors which link the component to both the battery and the chassis. To help to pinpoint a problem in an electrical circuit, wiring diagrams are Included at the end of this manual. 2 Before attempting to diagnose an electrical fault, first study the appropriate wiring diagram, to obtain a more complete understanding of the components included In the particular circuit concerned. The possible sources of a fault can be narrowed down by noting whether other components related to the circuit are operating properly. If several components or circuits fait at one time, the problem Is likely to be related to a shared fuse or earth connection.