Content .. 6 7 8 9 ..

Opel Corsa / Vauxhall. Manual - part 8

Contact breaker ignition system 5B•5

7.6a Remove the vacuum unit retaining

7.6b . . . and disengage the operating arm

7.7 Undo the baseplate retaining screws

screws (arrowed) . . .

(arrowed) while withdrawing the unit

(arrowed)

weights for cleaning or inspection, this can

and springs in position, hold the skew gear at

number of degrees BTDC when the marks are

now be done. Mark each spring and its

the base of the shaft with one hand, and with

aligned, not TDC.

associated locating post with a dab of paint

the other hand turn the upper shaft clockwise

4 Run the engine up to its normal operating

for identification and then carefully hook off

as far as it will go and then release it. Check

temperature and then switch off.

the springs. Ensure that the springs and

as this is done, that the advance weights

5 Connect a timing light to the spark plug

weights are refitted in the same positions

move out and then return under the action of

lead of No

1 cylinder, following the

otherwise the ignition advance characteristics

the springs. Finally check the drivegear for

manufacturer’s instructions.

of the engine will be altered. The weights can

wear, chips or pitting of the teeth. It will be

6 With the engine idling, point the timing light

be withdrawn after extracting the small

necessary to renew the complete distributor if

at the timing marks. The marks will appear

retaining clips (see illustration).

the body, shafts, weights, springs or drivegear

stationary, and if the timing is correct, they will

9 With the distributor dismantled, clean the

are worn or are in any way unsatisfactory.

be aligned.

mechanical components in paraffin and dry

15 Reassembly of the distributor is a direct

7 If the marks are not aligned, slacken the

with a lint-free cloth.

reversal of the removal sequence, but apply a

distributor clamp bolts or retaining nuts and

10 Check the condition of the contact

few drops of engine oil to the locating pivot

move the distributor body slowly in one

breaker points, as described in Section 3.

posts of the advance weights and to the felt

direction or the other until the marks line up.

Check the distributor cap for corrosion of the

pad at the top of the distributor shaft. After

Tighten the clamp bolt or retaining nuts and

segments and for signs of tracking, indicated

reassembly adjust the contact breaker points,

check that the setting has not altered.

by a thin black line between the segments.

as described in Section 3, and then refit the

8 Open the throttle slightly and note the

Make sure that the carbon brush in the centre

distributor to the car, as described in Section 6.

movement of the timing marks. If the

of the cap moves freely and stands proud by

centrifugal advance in the distributor is

at least 6 mm. Renew the cap if necessary.

working correctly the marks should appear to

move away from each other as the engine

11 If the metal portion of the rotor arm is

8 Ignition timing - adjustment

speed increases. The same should happen if

badly burned or loose renew the arm. If

suction is applied to the vacuum advance

slightly burnt, clean the arm with a fine file.

pipe after disconnecting it from the

12 Check that the plates of the baseplate

Models using leaded (4-star) petrol

carburettor, indicating that the distributor

assembly move freely, but without excessive

1 For prolonged engine life, efficient running

vacuum unit is satisfactory.

slackness. If defective the baseplate

performance and economy it is essential for

9 After checking the timing, switch off the

assembly must be renewed.

the fuel/air mixture in the combustion

engine and disconnect the timing light, if

13 Suck on the end of the vacuum unit outlet

chambers to be ignited by the spark plugs at

removed, refit the vacuum pipe to the

and check that the operating arm moves in as

precisely the right moment in relation to

carburettor.

the suction is applied. Release the suction

engine speed and load. For this to occur the

and check that the arm returns to its original

Models using unleaded petrol

ignition timing must be set accurately and

position. If this is not the case, renew the

should be checked at the intervals given in

Early (pre February 1985) models

vacuum unit.

Chapter 1 or wherever the position of the

14 Inspect the distributor body and shaft

10 On models produced up to February

distributor has been altered. To make an

assembly for excessive side movement of the

1985, no adjustment of the ignition timing is

accurate check of the ignition timing it is

shaft in its bushes. With the advance weights

necessary if the vehicle is to be run on

necessary to use a stroboscopic timing light,

unleaded fuel

(See Chapter

4A for fuel

whereby the timing is checked with the engine

requirement).

running at idling speed.

Later (February 1985 on) models

2 If the distributor has been removed, or if for

any reason its position on the engine has

11 All models produced after February 1985

been altered, obtain an initial setting to enable

are designed to run on unleaded, but the

the engine to be run, as described in Section

manufacturers state that the ignition should

6. Also make sure that the contact breaker

be retarded by 3º, to 7º BTDC.

points gap or dwell angle is correctly set, as

12 The crankshaft pulley only has one timing

described in Section 3.

mark (10º BTDC), so it will be necessary to

3 To check the timing, first highlight the

make additional marks to accurately retard

timing marks using white chalk or

the ignition.

quick-drying paint. The marks are a notch on

13 Turn the engine by means of the

the crankshaft pulley and a raised mark on the

crankshaft pulley bolt, or by engaging top

7.8 Centrifugal advance springs (A) and

timing cover (see illustration 6.3). When they

gear and pulling the car forward, until No 1

advance weight retaining clips (B)

are aligned the engine is at the specified

piston is at TDC on the firing stroke. This can

5B•6 Contact breaker ignition system

be felt by removing No 1 spark plug and

are two sets of each windings. Compare the

feeling for compression with your fingers as

9 Ignition HT coil - removal,

results obtained to those given in the

the engine is turned. The precise TDC point

testing and refitting

Specifications at the start of this Chapter.

will have to be determined using a blunt probe

Note the resistance of the coil windings will

(such as a knitting needle) inserted through

vary slightly according to the coil temperature,

Removal

the results in the Specifications are

No 1 spark plug hole.

1 Disconnect the battery leads.

approximate values for when the coil is at

14 Make a mark on the crankshaft pulley in

2 Disconnect the LT wiring connectors from

20ºC.

alignment with the timing mark, or pointer, on

the coil, noting there correct fitted positions.

6 Check that there is no continuity between

the engine.

3 Disconnect the HT lead from the coil.

the HT lead terminal and the coil

15 The original pulley mark indicates 10º

4 Undo the retaining bolts and remove the

body/mounting bracket.

BTDC, and the new mark TDC. Using these

coil from the car.

7 If the coil is thought to be faulty, have your

two markings, measure out a make a third

findings confirmed by a Vauxhall dealer before

mark on the pulley in the 7ºBTDC position.

Testing

renewing the coil.

16 Using the new timing mark, adjust the

5 Testing of the coil consists of using a

ignition timing as described in paragraphs 4 to

Refitting

multimeter set to its resistance function, to

7. If detonation occurs, it may be necessary to

check the primary (LT ‘+’ to ‘-’ terminals) and

8 Refitting is a reversal of the relevant

retard the ignition timing even further; some

secondary

(LT

‘+’ to HT lead terminal)

removal procedure ensuring that the wiring

experimentation may be worthwhile to

windings for continuity, bearing in mind that

connectors are correctly and securely

achieve satisfactory running.

on the four output, static type HT coil there

reconnected.

5C•1

Chapter 5 Part C:

Electronic (breakerless) ignition systems

Contents

Distributor - overhaul

Ignition module (control unit) - removal and refitting

Distributor - removal and refitting

Ignition system check

See Chapter 1

General information

Ignition system - testing

Ignition HT coil - removal, testing and refitting

Ignition timing - adjustment

Degrees of difficulty

Easy, suitable for

Fairly easy, suitable

Fairly difficult,

Difficult, suitable for

Very difficult,

novice with little

for beginner with

suitable for competent

experienced DIY

suitable for expert

experience

some experience

DIY mechanic

mechanic

DIY or professional

Specifications

General

Type

Breakerless electronic ignition system

System type:

1.3 and 1.4 litre carburettor models

AC Delco system

1.4 and 1.6 litre fuel injection models

Multec MSTS-h Hall effect trigger, microprocessor controlled advance

(integral with Multec CFi system)

1.6 litre carburettor models:

16SH engine models

Hall effect trigger distributor

16SV engine models:

Pre 1988 models

Inductive trigger, microprocessor controlled advance type MZV

1989 onwards models

Hall effect trigger, microprocessor controlled advance type E1 Plus

(also known as EZ Plus)

1.8 litre models:

18E engine models

Hall effect trigger distributor

18SE engine models

Inductive trigger, microprocessor controlled advance type E1 61

(formerly known as EZ 61)

2.0 litre models

Inductive trigger, microprocessor controlled advance (integral with

Bosch Motronic system)

Firing order

1-3-4-2 (No 1 at timing belt end of engine)

Rotational direction of distributor rotor arm

Anti-clockwise (viewed from cap)

Ignition timing

At idle (with vacuum pipe disconnected - early models only):

1.4 litre models

5º BTDC

All other models

10º BTDC

Ignition coil

Primary winding resistance (approximate)

1.2 to 1.6 ohm

Secondary winding resistance (approximate)

7k ohms

Torque wrench settings

lbf ft

Spark plugs

The distributor contains an induction

AC voltage is created. The module uses this

sensor (reluctor) mounted onto its shaft and

voltage to switch the transistors in the unit and

1 General information

an ignition module (pick-up) fixed to its body.

complete the ignition system primary (LT) circuit.

The system operates as follows.

As the teeth move out of alignment with the

When the ignition is switched on but the

module projections the AC voltage changes

1.3 and 1.4 litre carburettor models

engine is stationary the transistors in the

and the transistors are switched again to

module prevent current flowing through the

On all 1.3 litre models a Delco breakerless

interrupt the primary (LT) circuit. This causes a

ignition system primary (LT) circuit.

electronic ignition system is used. The system

high voltage to be induced in the coil

As the crankshaft rotates, the induction

comprises solely of the HT ignition coil and

sensor moves through the magnetic field

secondary (HT) windings which then travels

the distributor, the distributor being driven off

created by the module. When the teeth are in

down the HT lead to the distributor and onto

the end of the camshaft.

alignment with the module projections a small

the relevant spark plug.

5C•2 Electronic (breakerless) ignition systems

1.6 litre (16SH engine) models and

signals are derived from an inductive pulse

Carburettor models and 1.8 litre

1.8 litre (18E engine) models

sensor mounted on the front face of the

(18E engine) models

cylinder block and a segmented disc attached

On these models a Bosch (Hall effect)

Note: Refer to the warning given in Section 1

to the crankshaft No 1 counterweight.

ignition system is fitted. The system

of Part A of this Chapter before starting work.

The distributor in this system serves only to

comprises of the HT ignition coil, the

Always switch off the ignition before

distribute HT voltage to the correct cylinders.

distributor and the ignition module.

disconnecting or connecting any component

The distributor position is not adjustable and

The Hall effect system distributor

and when using a multi-meter to check

has no effect on ignition timing. The only

incorporates a permanent magnet, a

resistances.

alteration possible to the timing is by means

detector/amplifier, and four vanes. When a

of the octane rating coding plug.

General

vane is masking the detector/amplifier no

1 The components of electronic ignition

voltage is induced in the detector, and under

1.4 and 1.6 litre fuel injection

systems are normally very reliable; most faults

these conditions the module passes current

models

are far more likely to be due to loose or dirty

through the low tension windings of the coil.

The MULTEC CFi engine management

connections or to “tracking” of HT voltage

Rotation of the distributor will uncover the

system is described in Chapter

4B. The

due to dirt, dampness or damaged insulation

detector and cause it to be influenced by the

system is regulated by an Electronic Control

than to the failure of any of the system’s

magnetic field of the permanent magnet. The

Unit (ECU) which is continuously supplied

components. Always check all wiring

Hall effect induces a small voltage in the

information from various engine, cooling

thoroughly before condemning an electrical

detector plate which is then amplified and

system and fuel system sensors. The ECU is

component and work methodically to

triggers the module to interrupt the low

then able to make the necessary adjustments

eliminate all other possibilities before deciding

tension current in the coil.

to the fuel and ignition systems in accordance

that a particular component is faulty.

The ignition module in the Hall effect

with the continuously changing demands of

2 The old practice of checking for a spark by

system incorporates a circuit which switches

the engine. The ECU also has a diagnostic

holding the live end of an HT lead a short

off the low tension circuit if the time between

function, which can be used in conjunction

distance away from the engine is not

consecutive signals exceeds 1.5 seconds.

with special Vauxhall test equipment, for fault

recommended; not only is there a high risk of

The coil and internal circuits are therefore

diagnosis in the ignition system.

a powerful electric shock, but the HT coil or

protected if the ignition is left switched on

With the exception of basic checks to

amplifier unit will be damaged. Similarly,

inadvertently.

ensure that all relevant wiring and

never try to “diagnose” misfires by pulling off

connections are in good condition and

1.6 litre (16SV engine) models

one HT lead at a time.

securely connected, fault diagnosis should be

Engine will not start

Pre 1988 models

entrusted to a Vauxhall dealer.

3 If the engine either will not turn over at all,

The MZV system is fitted to the 16SV

2.0 litre models

or only turns very slowly, check the battery

engine in 1987 and 1988 model years. It is an

The Motronic systems are fully described in

and starter motor. Connect a voltmeter across

electronic system in which the amount of

Chapter 4B. The ignition side is very similar to

the battery terminals (meter positive probe to

ignition advance is controlled by a

the E1 61 system described earlier. Again, no

battery positive terminal), disconnect the

microprocessor which receives information on

alteration to the timing is possible except via

ignition coil HT lead from the distributor cap

engine speed, temperature and load. A

the octane rating plug.

and earth it, then note the voltage reading

correction can also be applied for small

The Motronic M2.5 system fitted to

obtained while turning over the engine on the

changes in fuel octane rating by means of the

16-valve models compensates for small

starter for (no more than) ten seconds. If the

octane rating coding plug. The initial ignition

changes in fuel octane rating automatically as

reading obtained is less than approximately

timing is still determined by distributor

part of the knock control function. The control

9.5 volts, first check the battery, starter motor

position. The distributor LT pulse generator is

unit contains two ignition timing ‘maps’, one

and charging system as described in the

of the inductive sensor type.

for high octane fuel and one for lower octane.

relevant Sections of this Chapter.

A basic adjustment coding plug is provided

If the engine knocks frequently, the control

4 If the engine turns over at normal speed but

for use when checking the initial ignition

unit switches to the low-octane map. A steady

will not start, check the HT circuit by

timing. When disconnected, this prevents the

period free of knocking will cause a switch

connecting a timing light

(following the

control unit from applying ignition advance.

back to the high-octane map. On the C20XE

manufacturer’s instructions) and turning the

1989 onwards models

engine the maps are for 91 and 95 octane

engine over on the starter motor; if the light

fuel; on the others they are for 95 and 98

The E1 Plus system (also known as EZ Plus)

flashes, voltage is reaching the spark plugs,

octane. 91 octane fuel must not be used in the

is a development of the MZV system.

so these should be checked first. If the light

engines which are not programmed for it.

Externally the components are very similar,

does not flash, check the HT leads

but the distributor LT pulses are now

themselves followed by the distributor cap,

produced by a Hall Effect sensor instead of

carbon brush and rotor arm using the

2 Ignition system - testing

inductively. The microprocessor control unit

information given in Chapter 1.

incorporates a self-diagnosis facility for fault

5 If there is a spark, check the fuel system for

detection, but this is only accessible to

faults referring to the relevant part of Chapter

Vauxhall dealers or other specialists with

4 for further information.

Warning: Voltages produced by

dedicated test equipment. The control unit

6 If there is still no spark, check the voltage at

an electronic ignition system are

also limits engine maximum speed by cutting

the ignition HT coil “+” terminal; it should be

considerably higher than those

off the LT pulses to the coil above 6000 rpm.

the same as the battery voltage (ie, at least

produced by conventional ignition

11.7 volts). If the voltage at the coil is more

systems. Extreme care must be

1.8 litre (18SE engine) models

taken when working on the system with the

than 1 volt less than that at the battery, check

The E1 61 system (also known as EZ 61) is

ignition switched on. Persons with

the feed back through the fusebox and

fitted to all 1.8 litre engines from 1987 model

surgically-implanted cardiac pacemaker

ignition switch to the battery and its earth until

year. Like the MZV and E1 Plus systems it

devices should keep well clear of the ignition

the fault is found.

uses a microprocessor control unit to

circuits, components and test equipment

7 If the feed to the HT coil is sound, check the

calculate dynamic ignition advance. LT

coil’s primary and secondary winding

Electronic (breakerless) ignition systems 5C•3

3.3 Crankshaft pulley timing notch

3.4 Disconnecting the distributor wiring

3.5 Removing the distributor from the

(arrowed) aligned with pointer (1.3 litre

connector at the ignition coil

camshaft housing

model shown, others similar)

resistance as described later in this Section;

in the distributor cap. If HT is present on all

those described in Chapter 1, relating to the

renew the coil if faulty, but be careful to check

leads, the fault will be in the spark plugs;

spark plugs, and the ignition coil test

carefully the condition of the LT connections

check and renew them if there is any doubt

described in this Chapter. If necessary, the

themselves before doing so, to ensure that

about their condition.

system wiring and wiring connectors can be

the fault is not due to dirty or poorly-fastened

14 If no HT is present, check the HT coil; its

checked as described in Chapter 12 ensuring

connectors.

secondary windings may be breaking down

that the control unit wiring connector(s) have

first been disconnected.

8 If the HT coil is in good condition, the fault

under load.

is probably within the control unit or

1.8 litre (18SE engine) models and

distributor assembly. Testing of these

3 Distributor - removal and

all 1.4, 1.6 and 2.0 litre fuel

components should be entrusted to a

refitting

injection models

Vauxhall dealer.

15 If a fault appears in the ignition system

Engine misfires

first ensure that the fault is not due to a poor

Removal

9 An irregular misfire suggests either a loose

electrical connection or poor maintenance; ie,

connection or intermittent fault on the primary

1.3 and 1.4 litre carburettor models

check that the air cleaner filter element is

circuit, or an HT fault on the coil side of the

clean, the spark plugs are in good condition

1 Remove the spark plugs (Chapter 1).

rotor arm.

and correctly gapped, that the engine

2 Undo the distributor cap retaining screws,

10 With the ignition switched off, check

breather hoses are clear and undamaged,

lift of the cap and place it to one side.

carefully through the system ensuring that all

referring to Chapter 1 for further information.

3 With the transmission in gear and the

connections are clean and securely fastened.

Also check that the accelerator cable is

handbrake released, pull the car forwards,

If the equipment is available, check the LT

until, with a finger over the plug hole,

correctly adjusted as described in the relevant

circuit as described above.

part of Chapter 4. If the engine is running very

compression can be felt in No 1 cylinder (the

11 Check that the HT coil, the distributor cap

cylinder nearest the crankshaft pulley).

roughly, check the compression pressures as

and the HT leads are clean and dry. Check the

Continue moving the car forwards until the

described in Chapter 2.

leads themselves and the spark plugs (by

notch on the crankshaft pulley is aligned with

16 If these checks fail to reveal the cause of

substitution, if necessary), then check the

the timing pointer

(see illustration).

(On

the problem the vehicle should be taken to a

distributor cap, carbon brush and rotor arm as

automatic transmission models, turn the

suitably equipped Vauxhall dealer for testing

engine by means of a spanner on the

described in Chapter 1.

using special diagnostic equipment. The

crankshaft bolt.) If the distributor cap is

12 Regular misfiring is almost certainly due to

tester will locate the fault quickly and simply

temporarily placed in position, the distributor

a fault in the distributor cap, HT leads or spark

alleviating the need to test all the system

rotor should be pointing towards the No 1

plugs. Use a timing light (paragraph 4 above)

components individually which is a time

spark plug lead segment in the cap.

to check whether HT voltage is present at all

consuming operation that carries a high risk of

4 Disconnect the distributor wiring connector

leads.

damaging the control unit.

at the ignition coil

(see illustration), and

13 If HT voltage is not present on any

17 The only ignition system checks which

detach the vacuum advance pipe from the

particular lead, the fault will be in that lead or

can be carried out by the home mechanic are

distributor vacuum unit.

5 Undo the distributor clamp retaining nut (or

bolt), lift off the clamp plate, and withdraw the

distributor from the camshaft housing (see

illustration).

1.6 litre carburettor models and 1.4,

1.6 and 1.8 litre (18E engine) fuel

injection models

6 The procedure is similar to that just

described in paragraphs 1 to 5, with the

following differences.

a) The wiring connector must be unplugged

from the distributor, not from the coil (see

illustration).

3.6a Unplugging the distributor LT

3.6b Removing the distributor cap (1.6 litre

b) The distributor cap is secured by two

connector (1.6 litre carburettor model

carburettor model shown)

spring clips, not by screws (see

shown)

illustration).

5C•4 Electronic (breakerless) ignition systems

3.6c Removing the flash shield to expose

3.6d Removing the distributor upper

3.6e Removing the distributor - note peg-

the No 1 cylinder reference mark (arrowed)

securing nut (1.6 litre carburettor

and-hole drive (1.6 litre carburettor

(1.6 litre carburettor model shown)

model shown)

c) There is a mark on the edge of the

fit in the housing, via an O-ring seal located in

from the coil or from the distributor cap.

distributor body to indicate the rotor

a groove on its outer edge, so ease it out of

16 Remove the two bolts which secure the

contact position for No 1 cylinder firing,

position taking great care not to damage the

distributor to the cylinder head

(see

but the rotor and flash shield must be

rotor arm (see illustration).

illustration).

removed to expose it (see illustration).

10 Undo the two retaining screws and

17 Withdraw the distributor complete with

The rotor can then be refitted to confirm

remove the rotor arm (see illustrations).

cap and HT leads. Note how the offset peg on

the alignment.

the distributor drive fits into the hole in the

11 If necessary, extract the rotor hub and

d) The distributor is secured by two nuts, not

exhaust camshaft (see illustration).

carefully lever the oil seal out from the cylinder

by a clamp plate. Where no mark is

head (see illustrations).

present make one with a scriber or dot of

Refitting

2.0 litre 8-valve models

white paint (see illustration).

1.3 and 1.4 litre carburettor models

e) The distributor drive is by means of an

12 Refer to paragraphs 7 to 11.

18 Before refitting the distributor, check that

offset peg and hole, not by a slot and

2.0 litre 16-valve models

the engine has not been inadvertently turned

dogs (see illustration).

13 Disconnect the battery earth (negative)

whilst the distributor was removed; if it has,

1.8 litre (18SE engine) models

lead.

return it to the original position as described in

7 Disconnect the battery leads.

14 Disconnect the Hall sensor multi-plug

paragraph 3.

8 Undo the retaining screws and remove the

from the distributor (see illustration).

19 Position the distributor so that the rotor

distributor cap from the distributor

(see

15 Remove the spark plug lead cover and

contact is in line with the arrow or notch in the

illustration).

disconnect the leads from the plugs.

distributor body. In this position, the offset lug

9 Extract the insulator. This is an interference

Disconnect the HT distributor-to-coil lead

on the distributor drive coupling will be in the

3.8 On 1.8 litre (18SE engine) models, undo

3.9 Extract the insulator

3.10a Undo the two Allen screws . . .

the distributor cap retaining screws

3.10b . . . and remove the rotor

3.11a Extract the rotor hub . . .

3.11b . . . and prise out the oil seal

Electronic (breakerless) ignition systems 5C•5

3.14 On 2.0 litre 16-valve models,

3.16 . . . then undo the retaining bolts . . .

3.17 . . . and remove the distributor

disconnect the Hall sensor wiring . . .

3.19a Distributor rotor contact, and arrow

3.19b . . . causing the drive coupling to be

3.19c . . . to engage the offset slot in the

on distributor body (circled) in alignment . . .

aligned like this . . .

camshaft

correct position to engage the similarly-offset

cylinder head, making sure its sealing lip is

procedure. Renew the O-ring seal if

slot in the end of the camshaft

(see

facing inwards. If necessary, tap the seal into

necessary. The distributor can only be fitted in

illustrations).

position using a suitable tubular drift which

one position and its fixings are not slotted as

20 Check that the O-ring seal is in place on

bears only on its hard outer edge.

it has no direct influence on the ignition

the distributor body, then insert the distributor

25 Carefully ease the rotor hub into position

timing.

into its camshaft housing location. With the

aligning its holes with the retaining bolt holes

rotor contact and arrow on the distributor

in the camshaft flange (see illustration).

body still in line, refit and secure the

26 Refit the rotor arm and securely tighten its

4 Distributor - overhaul

distributor clamp.

retaining screws.

21 Refit the distributor cap, spark plugs and

27 Fit a new O-ring to the groove in the

leads, wiring plug and vacuum pipe.

insulator. Apply a smear of oil to aid

1.3 and 1.4 litre carburettor models

22 Adjust the ignition timing (Section 5).

installation and ease the insulator into position

1 Remove the distributor from the engine, as

(see illustration).

1.6 litre carburettor models and 1.4,

described in the previous Section.

28 Refit the distributor cap, making sure it is

1.6 and 1.8 litre (18E engine) fuel

2 Undo the two retaining screws and lift off

correctly located, and securely tighten its

injection models

the rotor (see illustration).

retaining screws.

23 Refer to paragraphs 18 to 22, bearing in

3 Disconnect the two electrical plugs, one at

mind the information given in paragraph 6.

2.0 litre 8-valve models

each end, from the ignition module

(see

29 Refer to paragraphs 24 to 27.

illustration).

1.8 litre (18SE engine) models

4 Undo the two module retaining screws (see

2.0 litre 16-valve models

24 Lubricate the lips of the new seal and

illustration), and withdraw the unit from the

press the seal squarely into position in the

30 Refitting is the reverse of the removal

distributor.

5 Undo the two vacuum unit retaining screws

(see illustration), disengage the operating

rod and remove the vacuum unit.

6 Due to its design and construction, this is

the limit of dismantling possible on this

distributor. It is possible to renew the rotor,

vacuum unit, ignition module and distributor

cap separately, but if inspection shows any of

the components remaining on the distributor

to be in need of attention, the complete

distributor assembly must be renewed.

7 Check the distributor cap for corrosion of

the segments, and for signs of tracking,

3.25 Align the camshaft and rotor hub bolt

3.27 Renewing the insulator sealing ring

indicated by a thin black line between the

holes

segments. Make sure that the carbon brush in

5C•6 Electronic (breakerless) ignition systems

4.2 Exploded view of AC Delco breakerless

type distributor - 1.3 litre models

1 Distributor cap

2 Rotor

3 Shaft

4 Pin

5 Drive dog

6 Spring

7 Washer

8 Spring

9 O-ring

10 Body

11 Seal

12 Ignition module

13 Induction sensor

14 Circlip

15 Vacuum unit

16 Plug to coil

4.3 Disconnecting an electrical plug from

the ignition module

the centre of the cap moves freely, and stands

and that they return under the action of the

1.6 litre (16SH engine) and 1.8 litre

proud of its holder. Renew the cap if

springs. Check the security of all the

(18E engine) models

necessary.

components on the distributor shaft, and

8 If the metal portion of the rotor is badly

finally check for wear of the lug on the drive

13 Remove the distributor as described in

burnt or loose, renew the rotor. If slightly burnt

coupling.

Section 3.

it may be cleaned with a fine file.

11 Reassembly of the distributor is the

14 Pull off the rotor arm, and unclip the flash

9 Suck on the end of the vacuum unit outlet,

reverse sequence to dismantling, but apply a

shield (see illustration).

and check that the operating rod moves in as

few drops of engine oil to the advance weight

15 Although the top bearing plate can be

the suction is applied. Release the suction,

pivot posts before refitting the rotor. If a new

removed after undoing its retaining screws,

and check that the rod returns to its original

ignition module is being fitted, the new

this is of academic interest, since no spare

position. If this is not the case, renew the

module will be supplied with a small quantity

parts are available, neither are there any items

vacuum unit.

of silicone grease. This should be applied

requiring adjustment.

10 Inspect the distributor body and shaft

between the module and its housing, to

16 The vacuum unit can be renewed

assembly for excessive side movement of the

improve heat dissipation.

separately if required. Remove it by undoing

shaft in its bushes. Check that the advance

12 Refit the distributor as described in

the two retaining screws and unhooking the

weights are free to move on their pivot posts,

Section 3, after reassembly.

operating arm from the baseplate

(see

illustrations). Note that the screws are not of

equal length; the longer screw also secures

one of the distributor cap clips.

17 Test the vacuum unit, as described in

paragraph 9.

18 Inspect the distributor cap and rotor, as

described in paragraphs 7 and 8.

19 Reassemble the distributor in the reverse

order to that followed when dismantling.

Make sure that the vacuum unit operating arm

is correctly engaged with the peg on the

baseplate; several attempts may be needed to

reconnect it.

20 Refit the distributor as described in

4.4 Ignition module securing screws

4.5 Vacuum unit retaining screws

Section 3, after reassembly.

(arrowed)

Electronic (breakerless) ignition systems 5C•7

distributor is correctly refitted (Section 3), the

4.14 Exploded view of the Bosch breakerless type distributor -

timing should be accurate enough to start the

1.6 litre (16SH engine) and 1.8 litre (18E engine) models

engine and permit it to run.

2 Dynamic timing, using a stroboscopic

timing light, is carried out as described in Part

B, Section 8, paragraphs 10, 11 and 12. Note,

however, that the distributor is secured by

two nuts instead of a clamp bolt. Note also

that on 1.4 litre models, there are two timing

notches on the crankshaft pulley; the first

represents 10ºBTDC and the second 5ºBTDC

(see illustration).

3 Dwell angle checking and adjustment is not

necessary with breakerless distributors.

Models using unleaded petrol

4 The engines used in Cavalier models are

designed to run on high octane unleaded

petrol.

5 On 1.3 litre (13N and 13NB engines) low

compression engines, no modifications are

required and the ignition timing remains

unaltered. However, on all other models the

1 Vacuum unit

manufacturers recommend that the ignition

2 Body

timing is adjusted in accordance with the

3 Cap retaining clip

following guidelines.

4 O-ring

6 If detonation (“pinking” or “knock”) occurs,

5 Distributor cap

the timing should be retarded by 3° (see Part

6 Rotor

B, Section 8). If detonation occurs, it may be

7 Flash shield

necessary to retard the ignition timing even

8 Top bearing plate

further; some experimentation may be

9 Abutment ring

worthwhile to achieve satisfactory running.

All other models

7 On these models the ignition timing can be

checked using a stroboscopic light, but

1.6 (16SV engine) litre carburettor

adjustment is not possible. If the ignition

models and 1.4, 1.6 and 2.0 litre

timing is incorrect, the car should be taken to

16-valve fuel injection models

a Vauxhall dealer for testing/adjustment (as

21 Overhaul of the distributor should be

applicable).

entrusted to a Vauxhall dealer.

6 Ignition HT coil - removal,

1.8 litre (18SE engine) and 2.0 litre

8-valve models

testing and refitting

22 Refer to Section 3.

Removal

1 Disconnect the battery leads.

5 Ignition timing - adjustment

2 Disconnect the LT wiring connectors from

the coil, noting their correct fitted positions

4.16a Removing a vacuum unit retaining

(see illustration).

Warning: Voltages produced by

screw

3 Disconnect the HT lead from the coil. where

an electronic ignition system are

considerably higher than those

produced by conventional ignition

systems. Extreme care must be taken when

working on the system with the ignition

switched on. Persons with surgically-

implanted cardiac pacemaker devices

should keep well clear of the ignition circuits,

components and test equipment

1.3, 1.4 and 1.6 (16SH engine) litre

carburettor models and 1.8 litre

(18E engine) fuel injection models

Models using leaded (4-star) petrol

1 Static timing cannot be checked with the

4.16b Removing the vacuum unit

5.2 Crankshaft pulley timing marks -

breakerless ignition system. However, if the

1.4 litre carburettor models

5C•8 Electronic (breakerless) ignition systems

6.2 Disconnecting a coil LT lead (1.8 litre

6.3 Ignition module wiring plug

6.4a Removing a coil securing bolt

model shown)

Specifications at the start of this Chapter.

the coil, as described in Section 6.

Note the resistance of the coil windings will

3 With the coil removed from its bracket, the

vary slightly according to the coil temperature,

module can be unbolted from the mounting

the results in the Specifications are

plate (see illustration).

approximate values for when the coil is at

4 If a new module is being fitted, it should be

20ºC.

supplied with a small quantity of silicone

6 Check that there is no continuity between

grease, which must be applied to the

the HT lead terminal and the coil

mounting plate to improve heat dissipation

body/mounting bracket.

(see illustration). Similar heat sink

7 If the coil is thought to be faulty, have your

compounds can also be obtained from shops

findings confirmed by a Vauxhall dealer before

selling radio and electronic components.

renewing the coil.

5 Refit the ignition module in the reverse

order to removal. Make sure that the locating

Refitting

pins engage with the holes in the mounting

6.4b Undoing the coil clamp screw and nut

8 Refitting is a reversal of the relevant

plate.

removal procedure ensuring that the wiring

necessary, also disconnect the wiring

connectors are correctly and securely

1.6 litre (16SV engine) carburettor

connector from the ignition module

(see

reconnected.

models and 1.8 litre (18SE engine)

illustration).

fuel injection models

4 Undo the retaining bolts and remove the

6 The ignition control unit is located in the

7 Ignition module (control unit) -

coil from the car. If necessary, undo the clamp

engine compartment where it is mounted onto

removal and refitting

screw and remove the coil from its mounting

the suspension strut turret. To remove the

bracket (see illustrations).

unit, first disconnect the battery leads.

7 Release the spring retaining tangs and

Testing

1.3 and 1.4 litre carburettor models

disconnect the wiring connector

(see

5 Testing of the coil consists of using a

1 The ignition module is located in the

illustration).

multimeter set to its resistance function, to

distributor. See Section 4 for details.

8 Undo the retaining screws and remove the

check the primary (LT ‘+’ to ‘-’ terminals) and

unit from its mounting bracket.

1.6 (16SH engine) carburettor

secondary

(LT

‘+’ to HT lead terminal)

9 Refitting is the reverse of removal

models and 1.8 litre (18E engine)

windings for continuity, bearing in mind that

fuel injection models

on the four output, static type HT coil there

1.4 and 1.6 fuel injection models

2 The ignition module is located on the coil

and all 2.0 litre models

are two sets of each windings. Compare the

mounting plate. To gain access, first remove

results obtained to those given in the

10 Refer to Chapter 4.

7.3 Unbolting the ignition module (1.8 litre

7.4 Ignition module and mounting plate -

7.7 Disconnecting the control unit wiring

model shown)

note locating pins (arrowed), and heat sink

plug - later 1.8 litre model

compound on baseplate (1.8 litre model)

9•1

Chapter 9

Braking system

Contents

Anti-lock braking system (ABS) - general information

Hydraulic fluid renewal

See Chapter 1

Anti-lock braking system (ABS) components - removal and refitting .22

Hydraulic pipes and hoses - renewal

Brake pedal - removal and refitting

Hydraulic system - bleeding

Brake servo vacuum hose and non-return valve renewal

Master cylinder- removal and refitting

Front brake caliper - removal, overhaul and refitting

Pressure regulating valves - testing, removal and refitting

Front brake disc - inspection, removal and refitting

Rear brake caliper - removal, overhaul and refitting

Front brake pad wear check

See Chapter 1

Rear brake disc - inspection, removal and refitting

Front brake pads - renewal

Rear brake drum - removal, inspection and refitting

General information

Rear brake pad wear check

See Chapter 1

Handbrake - adjustment

See Chapter 1

Rear brake pads - renewal

Handbrake cable- removal and refitting

Rear brake shoe wear check

See Chapter 1

Handbrake lever- removal and refitting

Rear brake shoes - renewal

Handbrake shoes (rear disc brake models) - renewal

Rear wheel cylinder - removal, overhaul and refitting

Hydraulic fluid level check

See Chapter 1

Vacuum servo unit - testing, removal and refitting

Degrees of difficulty

Easy, suitable for

Fairly easy, suitable

Fairly difficult,

Difficult, suitable for

Very difficult,

novice with little

for beginner with

suitable for competent

experienced DIY

suitable for expert

experience

some experience

DIY mechanic

mechanic

DIY or professional

Specifications

Front brakes

Type

Disc, with single piston sliding caliper

Disc diameter:

2.0 litre models

256 mm

All other models

236 mm

Disc thickness:

New:

1.2 and 1.3 litre Saloon and Hatchback models

10.0 mm

1.3 litre Van and Estate models

12.7 mm

1.6 litre models

12.7 mm

1.8 litre models

20.0 mm

2.0 litre models

24.0 mm

Minimum thickness (after refinishing*):

1.2 and 1.3 litre Saloon and Hatchback models

8.0 mm

1.3 litre Van and Estate models

10.7 mm

1.6 litre models

10.7 mm

1.8 litre models

18.0 mm

2.0 litre models

22.0 mm

Brake pad thickness (including backing plate):

New

15.5 to 15.9 mm

Minimum

7.0 mm

*When this dimension is reached, only one more set of brake pads are permissible, then renew the discs

Rear brakes

Type:

2.0 litre GTE models

Disc, with twin piston caliper

All other models

Single leading shoe drum

Drum diameter:

New:

Pre 1989 models:

Hatchback and 1.3 litre Estates with manual transmission

200 mm

All other Estate models and all Vans

230 mm

1989 onwards models (all models)

200 mm

9•2 Braking system

Rear brakes (continued)

Drum diameter (continued):

Maximum diameter:

Pre 1989 models:

Hatchback and 1.3 litre Estates with manual transmission

201 mm

All other Estate models and all Vans

231 mm

1989 onwards models (all models)

201 mm

Maximum drum out-of-round

0.1 mm

Minimum friction material-to-rivet head depth

0.5 mm

Disc diameter

260 mm

Disc thickness:

New

10.0 mm

Minimum thickness (after refinishing*)

8.0 mm

Brake pad thickness (including backing plate):

New

15.0 mm

Minimum

7.0 mm

*When this dimension is reached, only one more set of brake pads are permissible, then renew the discs

Torque wrench settings

lbf ft

Bleed screws

Brake pipe/hose union

Front brake caliper:

GMF caliper:

Mounting bracket bolts

Caliper to mounting bracket bolts

ATE caliper:

Mounting bracket bolts

Slide bolts

Rear brake caliper mounting bolts

Wheel cylinder mounting bolt

Master cylinder mounting nuts

Wheel cylinder hydraulic union

Pressure regulating valve:

Rear axle mounted valve - Estate and Van

Master cylinder mounted valve:

GMF cylinder

ATE cylinder

Master cylinder stop screw (ATE)

Servo to bracket

Servo bracket to bulkhead

Rear brake backplate bolts (use thread-locking compound)

Handbrake lever bolts

ABS components:

Hydraulic unit to bracket bolts

Front wheel speed sensor bolt

Rear wheel speed sensor bolt

The hydraulic supply to the rear brakes is

handbrake provides a mechanical means of

regulated so that the front brakes always lock

operating the brake shoes.

1 General description

first under heavy braking. On Hatchback

Depending on operating territory and

models the regulation is by pressure-sensitive

equipment level, warning lights may be fitted

The footbrake operates on all four wheels.

valves screwed into the master cylinder; on

to indicate low brake fluid level, handbrake

Estate and Van models the valve is

On 2.0 litre GTE models disc brakes are fitted

application and brake pad wear. Sometimes

load-sensitive and is located near the rear

at both the front and rear, and on all other

one warning light has a dual function: refer to

axle, by whose movement it is modulated.

models, disc brakes are fitted at the front and

the owner’s handbook for details.

The brake servo is of the direct-acting type,

self-adjusting drums at the rear. On all

Note: When servicing any part of the system,

fitted between the pedal and the master

models, actuation is hydraulic with servo

work carefully and methodically; also observe

cylinder. It is powered by vacuum developed

assistance.

scrupulous cleanliness when overhauling any

in the inlet manifold. Should the servo fail, the

The hydraulic system is split into two

part of the hydraulic system. Always renew

brakes will still operate, but increased pedal

circuits, each circuit acting on one front and

components (in axle sets, where applicable) if

pressure will be required.

one diagonally opposite rear brake. In the

in doubt about their condition, and use only

The handbrake provides an independent

event of rupture of the hydraulic system in one

mechanical means of rear brake application.

genuine Vauxhall/Opel replacement parts, or

circuit, the remaining circuit will still function

On 2.0 litre GTE models the handbrake

at least those of known good quality. Note the

so that some braking capability remains. In

operates a set of brake shoes, the shoes act

warnings given in `Safety first’ and at relevant

such a case the pedal travel will increase and

on the brake drum which is incorporated

points in this Chapter concerning the dangers

greater effort will be needed.

inside the rear disc. On all other models, the

of asbestos dust and hydraulic fluid.

Braking system 9•3

basic (two-man) method must be used which

19 When no more air bubbles appear, tighten

is described in detail below.

the bleed screw securely, remove the tube

2 Hydraulic system - bleeding

9 If a kit is to be used, prepare the vehicle as

and spanner and refit the dust cap. Do not

described previously and follow the kit

overtighten the bleed screw.

manufacturer’s instructions as the procedure

20 Repeat the procedure on the remaining

Note: Hydraulic fluid is poisonous; wash off

may vary slightly according to the type being

screws in the sequence until all air is removed

immediately and thoroughly in the case of skin

used; generally they are as outlined below in

from the system and the brake pedal feels

contact and seek immediate medical advice if

the relevant sub-section.

firm again.

any fluid is swallowed or gets into the eyes.

10 Whichever method is used, the same

Certain types of hydraulic fluid are inflammable

Bleeding - using a one-way valve

and may ignite when allowed into contact with

sequence must be followed (paragraphs 11

kit

and 12) to ensure that the removal of all air

hot components; when servicing any hydraulic

from the system.

21 As their name implies, these kits consist of

system it is safest to assume that the fluid is

inflammable and to take precautions against

a length of tubing with a one-way valve fitted

Bleeding sequence

to prevent expelled air and fluid being drawn

the risk of fire as though it is petrol that is being

11 If the system has been only partially

back into the system; some kits include a

handled. Hydraulic fluid is also an effective

disconnected and suitable precautions were

translucent container which can be positioned

paint stripper and will attack plastics; if any is

taken to minimise fluid loss, it should be

so that the air bubbles can be more easily

spilt, it should be washed off immediately

necessary only to bleed that part of the

seen flowing from the end of the tube.

using large quantities of fresh water. Finally, as

system (ie. the primary or secondary circuit).

22 The kit is connected to the bleed screw,

it is hygroscopic (it absorbs moisture from the

air) - old fluid may be contaminated and unfit

12 If the complete system is to be bled, then

which is then opened. The user returns to the

for further use. When topping-up or renewing

it should be done in the following sequence.

driver’s seat and depresses the brake pedal

the fluid, always use the recommended type

Non ABS models

with a smooth, steady stroke and slowly

and ensure that it comes from a freshly opened

releases it; this is repeated until the expelled

a) Left-hand rear brake.

sealed container.

fluid is clear of air bubbles.

b) Right-hand front brake.

Note that these kits simplify work so

General

c) Right-hand rear brake.

much that it is easy to forget the master

d) Left-hand front brake.

1 The correct operation of any hydraulic

cylinder reservoir fluid level; ensure that this is

system is only possible after removing all air

Models equipped with ABS

maintained at least above the `MIN’ level line

from the components and circuit; this is

a) Left-hand front brake.

at all times.

achieved by bleeding the system.

b) Right-hand front brake.

Bleeding - using a pressure

2 During the bleeding procedure, add only

c) Left-hand rear brake.

bleeding kit

clean, unused hydraulic fluid of the

d) Right-hand rear brake.

recommended type; never re-use fluid that

24 These kits are usually operated by the

has already been bled from the system.

Bleeding - basic (two-man)

reservoir of pressurised air contained in the

Ensure that sufficient fluid is available before

method

spare tyre, although note that it will probably

starting work.

13 Collect a clean glass jar, a suitable length

be necessary to reduce the pressure to a

3 If there is any possibility of incorrect fluid

of plastic or rubber tubing which is a tight fit

lower limit than normal; refer to the

being already in the system, the brake

over the bleed screw and a ring spanner to fit

instructions supplied with the kit.

components and circuit must be flushed

the screw. The help of an assistant will also be

25 By connecting a pressurised, fluid-filled

completely with uncontaminated, correct fluid

required.

container to the master cylinder reservoir,

and new seals should be fitted to the various

14 Remove the dust cap from the first screw

bleeding can be carried out simply by opening

components.

in the sequence. Fit the spanner and tube to

each screw in turn (in the specified sequence)

4 If hydraulic fluid has been lost from the

the screw, place the other end of the tube in

and allowing the fluid to flow out until no more

system, or air has entered, because of a leak

the jar and pour in sufficient fluid to cover the

air bubbles can be seen in the expelled fluid.

ensure that the fault is cured before

end of the tube.

26 This method has the advantage that the

proceeding further.

15 Ensure that the master cylinder reservoir

large reservoir of fluid provides an additional

5 Park the vehicle on level ground, switch off

fluid level is maintained at least above the

safeguard against air being drawn into the

the engine and select first or reverse gear,

`MIN’ level line throughout the procedure.

system during bleeding.

then chock the wheels and release the

16 Have the assistant fully depress the brake

27 Pressure bleeding is particularly effective

handbrake.

pedal several times to build up pressure, then

when bleeding `difficult’ systems or when

6 Check that all pipes and hoses are secure,

maintain it on the final stroke.

bleeding the complete system at the time of

unions tight and bleed screws closed. Clean

17 While pedal pressure is maintained,

routine fluid renewal.

any dirt from around the bleed screws.

unscrew the bleed screw (approximately one

All methods

7 Unscrew the master cylinder reservoir cap

turn) and allow the compressed fluid and air to

and top the master cylinder reservoir up to the

flow into the jar. The assistant should maintain

28 On completion, when firm pedal feel is

`MAX’ level line; refit the cap loosely and

pedal pressure, following it down to the floor if

restored, wash off any spilt fluid, tighten the

remember to maintain the fluid level at least

necessary and should not release it until

bleed screws securely and refit the dust caps.

above the `MIN’ level line throughout the

instructed to do so. When the flow stops,

29 Check the hydraulic fluid level and top-up

procedure or there is a risk of further air

tighten the bleed screw again, release the pedal

if necessary (Chapter 1).

entering the system.

slowly and recheck the reservoir fluid level.

30 Discard any hydraulic fluid that has been

8 There are a number of one-man, do-it-

18 Repeat the steps given in paragraphs 16

bled from the system; it will not be fit for re-use.

yourself brake bleeding kits currently available

and 17 until the fluid emerging from the bleed

31 Check the feel of the brake pedal. If it

from motor accessory shops. It is

screw is free from air bubbles. If the master

feels at all spongy, air must still be present in

recommended that one of these kits is used

cylinder has been drained and refilled and air

the system and further bleeding is required.

whenever possible as they greatly simplify the

is being bled from the first screw in the

Failure to bleed satisfactorily after a

bleeding operation and also reduce the risk of

sequence, allow approximately five seconds

reasonable repetition of the bleeding

expelled air and fluid being drawn back into

between cycles for the master cylinder

procedure may be due to worn master

the system. If such a kit is not available the

passages to refill.

cylinder seals.

9•4 Braking system

3 Hydraulic pipes and hoses -

renewal

Note: Before starting work, refer to the note at

the beginning of Section 2 concerning the

dangers of hydraulic fluid.

1 If any pipe or hose is to be renewed,

minimise fluid loss by removing the master

cylinder reservoir cap and then tightening it

down onto a piece of polythene to obtain an

airtight seal. Alternatively flexible hoses can

be sealed, if required, using a proprietary

4.4a Removing an anti-rattle spring

4.4b Wear warning sensor clipped to pad

brake hose clamp, while metal brake pipe

unions can be plugged (if care is taken not to

allow dirt into the system) or capped

5 On refitting, do not overtighten the union

2 Inspect the thickness of the friction material

immediately they are disconnected. Place a

nuts. It is not necessary to exercise brute

on each pad. If any one is at or below the

wad of rag under any union that is to be

force to obtain a sound joint.

specified minimum, renew the pads as an axle

disconnected to catch any spilt fluid.

6 Ensure that the pipes and hoses are

set (four pads) in the following way.

2 If a flexible hose is to be disconnected,

correctly routed with no kinks and that they

unscrew the brake pipe union nut before

GMF and early ATE type caliper

are secured in the clips or brackets provided.

removing the spring clip which secures the

After fitting, remove the polythene from the

3 Drive out the pad retaining pins by applying

hose to its mounting bracket.

reservoir and bleed the hydraulic system as

a punch to their inboard ends.

3 To unscrew the union nuts it is preferable to

described in Section 2. Wash off any spilt fluid

4 Remove the springs and, where necessary,

obtain a brake pipe spanner of the correct

and check carefully for fluid leaks.

remove the pad wear warning sensor from the

size; these are available from most large

pad (see illustrations).

motor accessory shops. Failing this a close-

5 Using a pair of pliers, withdraw the

fitting open-ended spanner will be required,

outboard pad (see illustration).

4 Front brake pads - renewal

though if the nuts are tight or corroded their

6 Remove the inboard pad. If it is very tight,

flats may be rounded-off if the spanner slips.

move the pad sideways slightly to depress the

In such a case a self-locking wrench is often

Warning: Renew both sets of

caliper piston (see illustration).

the only way to unscrew a stubborn union, but

front brake pads at the same

7 In order to accommodate the new thicker

it follows that the pipe and the damaged nuts

time - never renew the pads on

pads, the caliper piston must be depressed

must be renewed on reassembly. Always

only one wheel as uneven

fully into its cylinder using a flat bar of metal

clean a union and surrounding area before

braking may result. Note that the dust

such as a tyre lever. The action of depressing

disconnecting it. If disconnecting a

created by wear of the pads may contain

the piston will cause the fluid in the reservoir

component with more than one union make a

asbestos, which is a health hazard. Never

to rise, so anticipate this by syphoning some

careful note of the connections before

blow it out with compressed air and don’t

off using an old (clean) hydrometer or similar.

disturbing any of them.

inhale any of it. An approved filtering

8 Brush out the jaws of the caliper, taking

4 If a brake pipe is to be renewed it can be

mask should be worn when working on

care not to inhale the dust.

obtained, cut to length and with the union

the brakes. DO NOT use petroleum-based

9 Insert the pads, making sure that the lining

nuts and end flares in place, from

solvents to clean brake parts. Use brake

side is against the disc. When fitting disc pads

Vauxhall/Opel dealers. All that is then

cleaner or methylated spirit only.

supplied by the vehicle manufacturer, it may

necessary is to bend it to shape, following the

be found that two pads out of the four have

line of the original, before fitting it to the car.

white marks on their backing plates. Where

Alternatively, most motor accessory shops

1 Raise the front of the vehicle (see “Jacking

this is the case, the pads with the marks

can make up brake pipes from kits, but this

and Vehicle Support”). If the roadwheels have

should be fitted to the piston sides of the

requires very careful measurement of the

been balanced on the vehicle (new vehicles

calipers.

original to ensure that the replacement is of

are balanced this way in production) then

10 Locate the springs correctly and drive in

the correct length. The safest answer is

mark the relative position of the roadwheel to

the retaining pins (see illustrations).

usually to take the original to the shop as a

the hub so that it can be aligned correctly

11 Repeat the operations on the opposite

pattern.

when refitting.

brake.

4.5 Removing the outboard pad

4.6 Removing the inboard pad

4.10a Inserting disc pad pin

Braking system 9•5

4.10b Pad retaining pins and anti rattle

4.16 On later ATE type calipers, unclip the

4.17 . . . then lever out the spring clip

springs correctly fitted

pad wear sensor . . .

12 Refit the roadwheels and lower the

20 Lift the caliper body and inboard pad off

tightening them to the specified torque. Fit the

vehicle.

the disc. The outboard pad will stay on the

dust caps.

13 Apply the footbrake hard several times to

bracket (see illustration). Support the caliper

25 Refit the pad wear warning sensor.

position the pads against the discs.

body, or tie it up with a piece of wire, so that

26 Carry out the operations described in

14 Top-up the fluid reservoir to the correct

the flexible hose is not strained.

paragraphs 11 to 15.

level.

21 Unclip the inboard pad from the caliper

15 New brake pads need to be carefully

piston and lift the outboard pad off the

bedded in and, where possible, heavy braking

bracket (see illustrations). Clean the caliper

5 Rear brake pads - renewal

should be avoided during the first 120 miles

and bracket.

(200 km).

22 If new pads are to be fitted, press the

piston back into its bore. As the piston is

Warning: Disc brake pads must

Later ATE type caliper

pushed back, the fluid level in the master

be renewed on both rear wheels

16 Extract the pad wear warning sensor and

cylinder will rise. Syphon some fluid out if

at the same time. Never renew

move it aside (see illustration).

necessary with an old (clean) poultry baster or

the pads on only one wheel as

17 Lever the ends of the spring clip from their

battery hydrometer.

uneven braking may result. Also, the dust

locations and remove the clip

(see

23 Make sure that the steps of the caliper

created by wear of the pads may contain

illustration).

piston are positioned as shown

(see

asbestos, which is a health hazard. Never

18 Remove the dust caps from the slide bolts

illustration).

blow it out with compressed air and don’t

(see illustration).

24 Fit the inboard pad to the piston and the

inhale any of it. An approved filtering

19 Using a 7 mm Allen key, unscrew the slide

outboard pad to the bracket. Fit the caliper to

mask should be worn when working on

bolts and remove them.

the bracket and secure it with the slide bolts

the brakes. DO NOT use petroleum-based

solvents to clean brake parts. Use brake

cleaner or methylated spirit only.

1 Raise the front of the vehicle (see “Jacking

and Vehicle Support”). If the roadwheels have

been balanced on the vehicle (new vehicles

are balanced this way in production) then

mark the relative position of the roadwheel to

the hub so that it can be aligned correctly

when refitting.

2 Inspect the thickness of the friction material

on each pad. If any one is at or below the

specified minimum, renew the pads as an axle

set (four pads) in the following way.

4.18 Removing a dust cap from a slide bolt

4.20 Lift the caliper off the disc . . .

3 Using a pin punch, drive out the two pad

retaining pins from the outside towards the

4.21a . . . then unclip the inboard pad from

4.21b . . . and remove the outboard pad

4.23 Prior to fitting the pads, ensure that

the caliper piston . . .

from the caliper bracket

the caliper steps are positioned as shown

9•6 Braking system

5.3 Driving out a rear disc pad retaining pin

5.9a Fitting a rear pad

5.9b Hooking the spring under one

retaining pin

middle of the vehicle

(see illustration).

anti-seize compound to the backs of the new

Recover the spring.

pads, and to the sides of the backplate. Be

6 Rear brake shoes - renewal

4 Remove the pads from the caliper. If they

careful not to get any on the friction surface.

are tight, use a slide hammer or grip them with

9 Insert the pads into the caliper with the

self-locking pliers.

friction material towards the disc. Fit one

Warning: Drum brake shoes

5 Clean the caliper with a soft wire brush,

retaining pin (from the inside towards the

must be renewed on both rear

paying attention to the warning at the

outside) and tap it home. Hook one end of the

wheels at the same time - never

beginning of this operation.

spring under the pin (see illustrations).

renew the shoes on only one

6 In order to accommodate the new thicker

10 Fit the other pin and tap it home, holding

wheel as uneven braking may result. Also,

pads, the caliper piston must be depressed

the other end of the spring down with a

the dust created by wear of the shoes may

fully into its cylinder using a flat bar of metal

screwdriver so that the pin passes over it.

contain asbestos, which is a health hazard

such as a tyre lever. The action of depressing

11 Repeat the operations on the opposite

Never blow it out with compressed air and

the piston will cause the fluid in the reservoir

brake.

don’t inhale any of it. An approved filtering

to rise, so anticipate this by syphoning some

12 Refit the roadwheels and lower the

mask should be worn when working on the

off using an old (clean) hydrometer or similar.

vehicle.

brakes. DO NOT use petroleum based

7 Inspect the brake disc for deep grooving,

13 Apply the footbrake hard several times to

solvents to clean brake parts. Use brake

scoring or cracks. Renew the disc, or have it

position the pads against the discs.

cleaner or methylated spirit only.

refinished if this is possible, if such damage is

14 Top-up the fluid reservoir to the correct

found. Excessive run-out may be caused by

level.

1 Remove the brake drum (Section 9).

wheel bearing play, so bearing adjustment

15 New brake pads need to be carefully

2 Working carefully and taking the necessary

should be checked before assuming that the

bedded in and, where possible, heavy braking

precautions, remove all traces of brake dust

disc is at fault.

should be avoided during the first 120 miles

from the brake drum, backplate and shoes.

8 Apply a little disc brake anti-squeal or

(200 km).

3 Measure the depth from the friction material

to each of the rivets. If this is equal or less than

6.5a Rear brake components with drum removed

the specified minimum, all four shoes must be

renewed as a set. Also, the shoes should be

1 Strut

renewed if any are fouled with oil or grease;

2 Thermoclip

there is no satisfactory way of degreasing

friction material once contaminated.

3 Adjuster pinion

4 If any of the brake shoes are worn unevenly

4 Adjuster lever

or fouled with oil or grease, trace and rectify

5 Adjuster lever spring

the cause before reassembly. If the shoes are

6 Adjuster lever bracket

to be renewed proceed as described below. If

7 Handbrake lever

all is well refit the drums (Section 9).

8 Upper return spring

5 Remove the steady pins, springs and

washers by depressing the washers and

turning them anti-clockwise. Renew them if

they are damaged (see illustrations).

6.5b Brake shoe steady pin and washer

(arrowed)

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