ECU OPEL CALIBRA 1988 Service Manual PDF

3The tensioner assembly, fitted to the
underside of the front seat, is maintenance
free and, once triggered, must be replaced as
a complete unit.
4Due to the specialist safety related nature
of the seat belt tensioner system, replacement
must be entrusted to a suitably equipped
Vauxhall dealer.
43Front seats (with seat belt
tensioners) -removal and
refitting
3
Removal
1Remove the single securing screw from the
front edge of the outer seat rail trim, release
the rear retaining lug and remove the trim
rearwards.
2Unclip the trim from the rear edge of the
inner seat rail.3Locate the plastic safety fork for the seat
belt tensioner, which is usually taped to the
outside of the tensioner spring cylinder.
4Insert the fork into the aperture provided at
the rear of the spring cylinder, ensuring that
the fork engages securely (see illustration).
5Remove the four bolts which secure the
seat rails to the floor, then withdraw the seat
complete with rails (see illustration). Recover
the washers and backplates.
6Seek the advice of a Vauxhall dealer if there
is any doubt about the condition of the seat
belt tensioner assembly.
Refitting
7Refitting is a reversal of removal. Note that
the manufacturers recommend the use of new
bolts to secure the seat rails to the floor.
Tighten the bolts to the specified torque
wrench settings (see Specifications) in the
order - rear inner, front inner, rear outer, front
outer.
11•22Bodywork and fittings
42.1 Mechanical seat belt tensioner system
1 Spring2 Bowden cable3 Fulcrum mechanism
43.5 Front outer seat rail fixings
1 Securing bolt
2 Seat belt tensioner safety fork (inserted
in the spring cylinder)43.4 Inserting the safety fork into the
aperture in the seat belt tensioner spring
cylinder
Warning: The seat belt
tensioners fitted to the front
seat assemblies may cause
injury if triggered inadvertently.
Before carrying out any work on the front
seats, a safety fork must be inserted into
the seat belt tensioner cylinder, to prevent
the possibility of the tensioner being
triggered (see paragraphs 7 and 8 below).
Seats should always be transported and
installed with the safety fork in place. If a
seat is to be disposed of, the tensioner
must be triggered before the seat is
removed from the vehicle, by inserting the
safety fork, and striking the tensioner
cylinder sharply with a hammer. If the
tensioner has been triggered due to a
sudden impact or accident, the unit must
be renewed, as it cannot be reset. Due to
safety considerations, tensioner renewal
should be entrusted to a Vauxhall dealer.

2Exhaust gas recirculation
(EGR) system - general
The system reintroduces small amounts of
exhaust gas into the combustion cycle to
reduce the generation of oxides of nitrogen
(NOx).
On C16 NZ, C16 NZ2 and C18 NZ engines,
the volume of exhaust gas reintroduced is
governed by manifold vacuum, through the
EGR valve mounted on the inlet manifold.
When the valve is opened small amounts of
exhaust gas are allowed to enter the inlet
tract, passing through ports in the cylinder
head.
On X16 SZ engines the EGR valve is
operated by an EGR module, mounted on the
left-hand side of the engine compartment
behind the battery. This module amplifies
signals received from the fuel system ECU
and operates the EGR valve electronically
providing precise control of exhaust gas
recirculation under all engine conditions.
3EGR valve (Multec system
models) - testing, removal and
refitting
2
Testing
1On C16 NZ, C16 NZ2 and C18 NZ engines,
it is recommended that the system is checked
annually, by checking the movement of the
valve’s diaphragm carrier plate as follows.
Note that the carrier plate is visible only
through the apertures in the underside of the
valve, so a battery-operated torch and small
mirror may be useful. On X16 SZ engines,
Vauxhall test equipment is necessary to check
the EGR system.
2With the engine fully warmed up to normal
operating temperature and idling, briefly open
and close the throttle. The carrier plate should
move upwards as the manifold vacuum
changes. When the engine is idling smoothly
again, press the carrier plate upwards (do this
very carefully, so that the plate is not distorted or
the diaphragm damaged). The idle speed should
drop significantly (approximately 100 rpm).
3If the valve does not respond as described,
it must be cleaned.
Removal
4Pull off the hose from the valve, then unbolt
the valve and remove it (see illustrations).
Clean away all carbon using a wire brush and
a pointed tool, but take care not to damage
the valve seat. Renew the valve gasket to
prevent induction leaks.
Refitting
5Refit the valve and reconnect the hose,
then recheck the system’s performance; if
there is no improvement, the valve must be
renewed.
4EGR valve (Simtec system) -
testing, removal and refitting
3
Note: A new gasket will be required when
refitting the valve.
Removal
1Disconnect the battery negative lead.
2Remove wiring harness and vacuum hose.
3Mark position of the valve, to ensure
correct relocation.
4Undo the 3 bolts, and remove the valve
from the dual spark ignition coil’s coolant
flange.
Refitting
5Clean the sealing surfaces of the valve and
flange.
6Refit the valve with a new gasket and line
up the marks made before removal (see
illustration).
5EGR module (X16 SZ
models) - removal and
refitting
2
Removal
1Disconnect the knock module from its
bracket (refer to Chapter 4B, if necessary),
and place to one side.
2Remove wiring plug from module. Remove
module from bracket.
Refitting
3Refitting is a reversal of removal.
6AIR pump assembly (Simtec
system) - removal and refitting
3
Removal
1Chock the rear wheels, jack up the front of
the vehicle and support it on axle stands
placed under the body side members (see
“Jacking and Vehicle Support”)
2Remove the left hand front wheel and inner
wheel arch lining.
3Loosen the hose clamp and remove the air
duct hose from the pump.
4Disconnect the battery negative lead.
5Undo the securing nuts and remove the
pump assembly from its location. Disconnect
the wiring plug.
6Remove the wiring plug from the pump’s
bracket.
7Mark the position of the pump on it’s
bracket before separating.
8Remove the fixing bolts and disconnect the
pump from it’s insulator.
9The insulator can also be checked by
removing the 3 nuts, securing the protective
shield. Before removing, mark the shield and
insulator. Replace if necessary.
10Check the pump’s air cleaner for damage.
Refitting
11Refitting is a reversal of removal. Ensure
correct alignment of the components.
7AIR cut-off valve - removal,
testing and refitting
3
Removal
1Before removal, mark on the cut-off valve,
the direction of flow towards the non-return
valve (see illustration).
2Disconnect and remove the air duct and
vacuum hoses.
3Undo the switchover valve’s bolts and
move to one side.
4C•2Fuel and exhaust systems - exhaust and emissions
3.4 Disconnecting the vacuum hose from
the exhaust gas recirculation valve
4.6 EGR valve
1 Valve 2 Gasket
3.4B Withdrawing the exhaust gas
recirculation valve

4The cut-off valve can now be removed from
the bracket.
Testing
5To test the cut-off valve a vacuum hand
pump with gauge will be required. If available,
connect to the cut-off valve and ensure that
air through-flow aperture is fully open.
Refitting
6Refitting is a reversal of removal. Ensure
valve is fitted in the correct direction.
8AIR switchover valve -
removal and refitting
3
Removal
1Disconnect the battery negative lead.
2Disconnect wiring plug from the valve.
3Mark the location of the vacuum hoses
before removing them from the valve.
4After disconnecting the hoses undo the two
bolts, and remove them from its bracket.
Refitting
5Refitting is a reversal of removal. Ensure
hoses are fitted correctly (see illustration).
9AIR pipe and non-return
valve - removal and refitting
3
Note:New air pipe washers will be required
when refitting.
Removal
1Remove the non-return valve air duct hose.
2Undo the bolts engine lifting eye bracket,
and turn the bracket on to its left hand side.
3Remove the pipe support bracket by
releasing its three bolts.
4Remove the heat shield that is secured by
two bolts.
5The air pipe can now be removed by
releasing the two securing bolts.
6If necessary the non-return valve can now
be disconnected.
7Carefully clamp the pipe using a vice with
protective jaws. Unbolt the valve from the
pipe, clean and inspect for damage.
Refitting
8Before refitting, coat the threads of the non-
return valve with sealing compound (i.e.
Vauxhall part no. 90094714).
9Use new washers when refitting the pipe,
(take care as the washers have sharp edges).
Coat the pipe mounting bolts with assembly
paste (i.e. Vauxhall part no. 90513210), before
refitting.
10Refitting is a reversal of removal.
Retighten to correct torque as shown in Spec-
ifications.
10Catalytic converter -
description, general and
precautions
Note: The catalytic converter is not a filter. It
creates a chemical reaction, but it is not
affected by that reaction.
Description
1Certain models are available with a catalytic
converter, to reduce exhaust emissions.
These models can be identified by a ‘C’ or ‘X’,
prefixing the engine code.
2The purpose of the catalytic converter is to
change potentially harmful hydrocarbon andcarbon monoxide exhaust gases into harmless
gases and water vapour. The converter
consists of a stainless steel canister containing
a catalyst-coated honeycomb ceramic. The
catalyst is a mixture of three precious metals,
platinum, palladium and rhodium.
3The exhaust gases pass freely through the
honeycomb, where the catalyst speeds up the
chemical change of the exhaust gases,
without being permanently altered itself.
4To avoid damage to the catalyst, the engine
must be kept properly tuned, and unleaded
petrol must always be used. Normal leaded
petrol will “poison” the catalyst, and must not
be used.
5To enable the Motronic engine management
system to achieve complete combustion of the
fuel mixture, and thus to minimise exhaust
emissions, an oxygen sensor is fitted in the
exhaust gas stream. The sensor monitors the
oxygen level in the exhaust gas, and sends a
signal to the Motronic module. The module
constantly alters the fuel/air mixture within a
narrow band to reduce emissions, and to allow
the catalytic converter to operate at maximum
efficiency. No adjustment of idle mixture is
therefore possible on models fitted with a
catalytic converter.
General
6Ninety-nine per cent of exhaust gases, from
a petrol engine (however efficient or well
tuned), consists of nitrogen (N
2), carbon
dioxide (CO
2), oxygen (O2), other inert gases
and water vapour (H
2O). The remaining 1% is
made up of the noxious materials that are
currently seen (except CO
2), as the major
polluters of the environment. Carbon
monoxide (CO), unburned hydrocarbons (HC),
oxides of nitrogen (NOx) and some solid
matter, including a small lead content.
7The device most commonly used to clean
up vehicle exhausts is the catalytic converter.
It is fitted into the vehicle’s exhaust system
and uses precious metals (platinum and
palladium or rhodium) as catalysts to speed
up the reaction between the pollutants and
the oxygen in the exhaust gases. CO and HC
being oxidised to form H
2O and CO2and (in
the three-way type of catalytic converter) NOx
being reduced to N
2.
8The converter consists of an element of
ceramic honeycomb, coated with a
combination of precious metals in such a way
as to produce a vast surface area over which
the exhaust gases must flow. The three-way
closed-loop type converter fitted to these
models can remove over 90% of pollutants.
9The catalytic converter is a reliable and
simple device that needs no maintenance.
However there are some facts that an owner
should be aware if the converter is to function
properly for its full service life (see
illustration).
a)DO NOT use leaded petrol in a vehicle
equipped with a catalytic converter. The
lead will coat the precious metals,
reducing their converting efficiency and
will eventually destroy the converter.
Fuel and exhaust systems - exhaust and emissions 4C•3
10.9 The catalytic converter is protected
by heat shields
8.5 AIR switchover valve
1 Connection to brake servo vacuum hose
2 Connection to cut-off valve
7.1 AIR cut-off valve
1 Connection to AIR pump
2 Connection to AIR switchover valve
3 Connection to AIR non-return valve
4C

b)Always keep the ignition and fuel systems
well maintained according to the
manufacturers schedule (see “Routine
maintenance” and the relevant Chapter).
In particular, ensure that the air cleaner
filter element, the fuel filter and the spark
plugs are renewed at the correct intervals.
If the inlet air/fuel mixture is allowed to
become too rich due to neglect, the
unburned surplus will enter and burn in
the catalytic converter, overheating the
element and eventually destroying the
converter.
c)If the engine develops a misfire, do not
drive the vehicle at all (or at least as little
as possible) until the fault is cured. The
misfire will allow unburned fuel to enter
the converter, which will result in its
overheating, as noted above.
d)The engine control indicator (the outline
of an engine with a lightning symbol
superimposed), will light when the ignition
is switched on and the engine is started,
then it will go out. While it may light briefly
while the engine is running, it should go
out again immediately and stays unlit. If it
lights and stays on while the engine is
running, seek the advice of a Vauxhall
dealer as soon as possible. A fault has
occurred in the fuel injection/ignition
system that, apart from increasing fuel
consumption and impairing the engine’s
performance, may damage the catalytic
converter.
e)DO NOT push or tow-start the vehicle.
This will soak the catalytic converter in
unburned fuel causing it to overheat when
the engine does start see (b) above.
f)DO NOT switch off the ignition at high
engine speeds. If the ignition is switched
off at anything above idle speed,
unburned fuel will enter the (very hot)
catalytic converter, with the possible risk
of its igniting on the element and
damaging the converter.
g)DO NOT use fuel or engine oil additives.
These may contain substances harmful to
the catalytic converter.
h)DO NOT continue to use the vehicle if the
engine burns oil to the extent of leaving a
visible trail of blue smoke. The unburned
carbon deposits will clog the converter
passages and reduce its efficiency; in
severe cases the element will overheat.
i)Remember that the catalytic converter
operates at very high temperatures hence
the heat shields on the vehicle’s under-
body and the casing will become hot
enough to ignite combustible materials
that brush against it. DO NOT, therefore,
park the vehicle in dry undergrowth, over
long grass or over piles of dead leaves.
j)Remember that the catalytic converter is
FRAGlLE. Do not strike it with tools during
servicing work. Take great care when
working on the exhaust system. Ensure
that the converter is well clear of any
jacks or other lifting gear used to raise thevehicle. Do not drive the vehicle over
rough ground, road humps, etc., in such a
way as to ground the exhaust system.
k)In some cases, particularly when the
vehicle is new and/or is used for
stop/start driving, a sulphurous smell (like
that of rotten eggs) may be noticed from
the exhaust. This is common to many
catalytic converter-equipped vehicles and
seems to be due to the small amount of
sulphur found in some petrol’s reacting
with hydrogen in the exhaust to produce
hydrogen sulphide (CS) gas. While this
gas is toxic, it is not produced in sufficient
amounts to be a problem. Once the
vehicle has covered a few thousand miles
the problem should disappear. In the
meanwhile a change of driving style or of
the brand of petrol may effect a solution.
l)The catalytic converter, used on a
well-maintained and well-driven vehicle,
should last for between 50 000 and 100
000 miles. From this point on, careful
checks should be made at all specified
service intervals of the CO level to ensure
that the converter is still operating
efficiently. If the converter is no longer
effective it must be renewed.
11Carbon canister - removal
and refitting
3
Removal
1Apply the handbrake, then jack up the front
of the vehicle, and support securely on axle
stands placed under the body side members
(see “Jacking and Vehicle Support”).
2Remove the front right hand wheel and
wheel arch liner.
3Note the hose and pipe connections to the
canister, or label them, to ensure that they are
reconnected to their original unions, then
disconnect them (see illustration). Unscrew
the two nuts securing the canister mounting
bracket to the vehicle body.
Refitting
4Refitting is a reversal of removal, however
ensure correct fitment of hose and pipes.
12Oxygen sensor (catalytic
converter models) - removal
and refitting
3
Note: This sensor is also known as a Lambda
sensor.
Removal
1Disconnect the battery negative lead.
2Disconnect the oxygen sensor wiring plug,
which is located behind the coolant expansion
tank.
3Apply the handbrake, then jack up the front
of the vehicle, and support securely on axle
stands placed under the body side members.
4On DOHC models, remove the engine
undershield, as described in Chapter 11.
5On models fitted with Multec injection
system, the sensor is screwed into the
exhaust manifold. Trace the wiring from the
sensor itself to the connector (either clipped
to the radiator cooling fan shroud or behind
the coolant expansion tank). Release it from
any clips or ties; disconnect the wiring before
unscrewing the sensor.
6On other models, unscrew the oxygen
sensor from the front section of the exhaust
system (see illustration). It is advisable to
wear gloves, as the exhaust system will be
extremely hot.
7Withdraw the oxygen sensor and its wiring,
taking care not to burn the wiring on the
exhaust system. If the sensor is to be re-used,
take care that the sealing ring is not lost, and
that the sensor is not dropped.
Refitting
8If a new sensor is being fitted, it will be
supplied with the threads coated in a special
grease to prevent it seizing in the exhaust
system.
9If the original sensor is being refitted,
ensure that the screw thread is clean. Coat
the thread with a lithium based copper grease
(i.e. Vauxhall Part No. 90295397).
10Refitting is a reversal of removal. Check
the exhaust system for leakage when the
engine is re-started.
4C•4Fuel and exhaust systems - exhaust and emissions
12.6 Oxygen sensor location in front
section of exhaust system - DOHC models
11.3 Charcoal canister
A Vent to atmosphere
B Vapour feed hose from filler pipe
C Vapour exhaust hose to inlet tract
D Control valve vacuum pipe from
throttle body

13Exhaust manifold - removal
and refitting
3
Note:New manifold-to-cylinder head, and
manifold-to-downpipe, gaskets must be used
on refitting. Exhaust manifolds on DOHC
models are of tubular design, which form part
of the front section of the exhaust.
Removal
1Disconnect the battery negative lead.
2Disconnect the HT leads from the spark
plugs, if necessary labelling them to ensure
refitting to the correct cylinders.
3Loosen the clamp screw and disconnect
the air cleaner hot air tube from the shroud on
the manifold, if fitted. Remove the securing
screws and withdraw the hot air shroud from
the manifold.
4Working under the manifold, unscrew and
remove the four bolts securing the exhaust
downpipe to the manifold.
5If fitted, disconnect the oxygen sensor
wiring
6Separate the downpipe from the manifold,
and support with wire or string. Do not allow
the front section of the exhaust system to hang
under its own weight. Recover the gasket.
7Unscrew the securing nuts, and withdraw
the manifold from the cylinder head (see
illustration). Recover the gasket.
8It is possible that some of the manifold
studs may be unscrewed from the cylinder
head when the manifold securing nuts are
unscrewed. In this event, the studs should be
screwed back into the cylinder head once the
manifold has been removed, using two
manifold nuts locked together.
Refitting
9Refit the manifold using a new gasket, and
tighten the securing nuts to the specified
torque.
10Reconnect the exhaust downpipe to the
manifold, using a new gasket and tighten the
securing bolts to the specified torque.
11Further refitting is a reversal of removal.
14Exhaust system - checking,
removal and refitting
2
Note: All relevant gaskets and/or sealing rings
should be renewed on refitting
Checking
1Periodically, the exhaust system should be
checked for signs of leaks or damage. Also
inspect the exhaust system rubber
mountings, and renew if necessary.
2Small holes or cracks can be repaired using
proprietary exhaust repair products, but
where more serious corrosion or damage is
evident, renewal will be necessary.
Removal
3The original factory-fitted exhaust system
consists of four separate sections, all of which
can be renewed individually.
4On models fitted with a catalytic converter,
an oxygen sensor is fitted to the front section
of the exhaust. The catalytic converter is fitted
in place of the front expansion box in the
conventional exhaust system. The
manufacturers do not specify any renewal
intervals for the catalytic converter.
5Before renewing an individual section of the
exhaust system, it is wise to inspect the
remaining sections. If corrosion or damage is
evident on more than one section of the
system, it may prove more economical to
renew the entire system.
6Individual sections of the exhaust system
can be removed as follows.
Front section - SOHC models
7On models with a catalytic converter,
disconnect the battery negative lead, and
disconnect the oxygen sensor wiring plug,
which is located behind the coolant expansion
tank.
8Raise the vehicle, and support securely on
axle stands placed under the body side
members (see “Jacking and Vehicle
Support”).
9Unscrew the two securing bolts, and
disconnect the exhaust front section from the
front expansion box or catalytic converter (as
applicable) at the flexible joint. Recover the
sealing ring and the springs (see illustration).10Unbolt the exhaust front section from the
bracket on the cylinder block (see
illustration).
11Unscrew and remove the four bolts
securing the downpipe to the exhaust
manifold, and withdraw the exhaust front
section (see illustration). Recover the
downpipe-to-manifold gasket.
Refitting
12Refitting is a reversal of removal, but use a
new gasket when reconnecting the downpipe
to the manifold, and a new sealing ring when
connecting the flexible joint. Tighten all fixings
to the specified torque.
Front section - DOHC models
Removal
13Proceed as described in paragraphs 7
and 8.
14Remove the engine undershield, as
described in Chapter 11.
15Proceed as described in paragraphs 9
and 10.
16Working in the engine compartment,
remove the bolts securing the exhaust
manifold heat shield to the cylinder head.
17Unscrew the two lower exhaust manifold
securing nuts that also secure the heat shield
brackets, and withdraw the heat shield (see
illustration).
18Unscrew the remaining manifold securing
nuts, then withdraw the manifold/exhaust
front section from the vehicle. Recover the
manifold gasket.
Fuel and exhaust systems - exhaust and emissions 4C•5
14.10 Exhaust front section support
bracket - SOHC models
14.11 Unscrewing a downpipe-to-exhaust
manifold bolt - SOHC models
14.9 Exhaust front section flexible joint -
SOHC models13.7 Unscrewing an exhaust manifold
securing nut - SOHC models
4C

19It is possible that some of the manifold
studs may be unscrewed from the cylinder
head when the manifold securing nuts are
unscrewed. In this event, the studs should be
screwed back into the cylinder head once the
manifold has been removed, using two
manifold nuts locked together.
Refitting
20Refitting is a reversal of removal, but use a
new manifold gasket, and use a new sealing
ring when reconnecting the flexible joint.
Tighten all fixings to the specified torque.
Front expansion box/catalytic
converter
Removal
21Proceed as described in paragraphs 8
and 9.
22Unscrew the three securing nuts and
bolts, and disconnect the expansion
box/catalytic converter from the exhaust
centre section flanged joint. Recover the
gasket.
23Withdraw the expansion box/catalytic
converter from the vehicle.
Refitting
24Refitting is a reversal of removal, but use a
new sealing ring when reconnecting the
flexible joint, and a new gasket when
reconnecting the flanged joint. Tighten all
fixings to the specified torque.
Centre section
Removal
25Raise the vehicle, and support securely on
axle stands placed under the body side
members.
26Unscrew the clamp bolt, and disconnect
the exhaust centre section from the rear
section (see illustration). If necessary, tap
around the joint with a hammer to break the
seal, and gently prise the two sections apart.
Note that the end of the centre section fits
inside the rear section, to form a sleeve joint.
27Proceed as described in paragraph 22.
28Release the exhaust centre section from
its rubber mountings on the underbody, and
withdraw it from the vehicle (see illustration).
Refitting
29Refitting is a reversal of removal, but use a
new gasket when reconnecting the flanged
joint, and lubricate the pipes with exhaust
assembly paste when connecting the centre
section to the rear section. Tighten all fixings
to the specified torque.
Rear section
Removal
30Proceed as described in paragraphs 25
and 26.
31Release the exhaust rear section from its
rubber mountings on the underbody, and
withdraw it from the vehicle.
Refitting
32Refitting is a reversal of removal, but
lubricate the pipes with exhaust assembly
paste when connecting the rear section to the
centre section. Tighten the clamp bolt to the
specified torque.
4C•6Fuel and exhaust systems - exhaust and emissions
14.28 Exhaust centre section forward
rubber mountings - DOHC models14.26 Exhaust centre section-to-rear
section clamp (arrowed) - SOHC model14.17 Exhaust manifold nut (arrowed)
securing exhaust heat shield - DOHC
models

Rear discs
Type (all models) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Solid
Diameter (all models) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .260 mm
Maximum disc run-out (all models) . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.1 mm
Minimum pad friction material thickness (including backing plate):
All models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.0 mm
Minimum disc thickness after machining (all models) * . . . . . . . . . . . . .8.0 mm
* When this dimension is reached, only one further new set of disc pads is permissible, then renew the discs
Minimum handbrake shoe friction material thickness (lining only)
All models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.0 mm
Rear drums
Internal diameter (all models) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .200 mm
Minimum shoe friction material thickness (all models) . . . . . . . . . . . . . .0.5 mm above rivet heads
Brake fluid type/specification:
All models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .See Lubricants and fluidsin “Weekly checks”
Torque wrench settingsNmlbf ft
ABS hydraulic modulator mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . .86
ABS wheel sensor mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86
ABS control unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.51
Brake fluid line unions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1612
Caliper and wheel cylinder bleed screws . . . . . . . . . . . . . . . . . . . . . . . .97
Front brake disc securing screw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
Front brake fluid hose to caliper union . . . . . . . . . . . . . . . . . . . . . . . . . .4030
Front caliper bracket to hub carrier . . . . . . . . . . . . . . . . . . . . . . . . . . . .9570
Front caliper guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3022
Front caliper mounting (solid disc models) . . . . . . . . . . . . . . . . . . . . . . .9570
Front caliper to mounting bracket (vented disc models) . . . . . . . . . . . .3022
Handbrake lever securing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2015
Master cylinder mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2216
Master cylinder stop screw (ATE type) . . . . . . . . . . . . . . . . . . . . . . . . . .64
Pressure proportioning valve to master cylinder:
ATE type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .129
GMF type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4030
Rear brake backplate/stub axle spring:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5037
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Angle-tighten a further 30º
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Angle-tighten a further 15º
Rear brake disc securing screw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86
Rear caliper mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8059
Rear drum securing screw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
Rear wheel cylinder mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .97
Vacuum servo support bracket to bulkhead . . . . . . . . . . . . . . . . . . . . .2216
Vacuum servo to support bracket . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2015
1General description
The foot brake operates on all four wheels.
Solid or ventilated disc brakes are fitted at the
front, and self-adjusting drum or solid disc
brakes are fitted at the rear, depending on
model. Actuation is hydraulic, with vacuum
servo assistance. The handbrake is cable-
operated, and acts on the rear wheels only.
The hydraulic system is split into two
circuits. On non-ABS models, the system is
split diagonally, and on ABS models, the
system is split front and rear. If there is a
hydraulic fluid leak in one circuit, the
remaining circuit will still function, so that
some braking capability remains.
The hydraulic fluid supply to the rear brakes
is regulated so that the front brakes alwayslock first under heavy braking. The fluid
pressure to the rear brakes is controlled by
two valves, one for each brake, which are
either screwed into the master cylinder or
mounted on the rear underbody of the vehicle,
depending on model.
The brake servo is of the direct-acting type,
fitted between the pedal and the master
cylinder. The servo is powered by vacuum
developed in the inlet manifold. Should the
servo fail, the brakes will still operate, but
increased pedal pressure will be required.
2Anti-lock braking system
(ABS) - general
1ABS is available as an option for all models.
When the ignition is switched on, an ‘ABS’
symbol illuminates in the instrument panel for
a short time. 2The system comprises an electronic control
unit, roadwheel sensors, hydraulic modulator,
and the necessary valves and relays. Disc
brakes are fitted to all four wheels. The
purpose of the system is to stop wheel(s)
locking during heavy brake applications. This
is achieved by automatic release of the brake
on the locked wheel, followed by re-
application of the brake. This procedure is
carried out several times a second by the
hydraulic modulator.
3The modulator is controlled by the
electronic control unit, which itself receives
signals from the wheel sensors, which monitor
the locked or unlocked state of the wheels.
The two front brakes are modulated
separately, but the two rear brakes are
modulated together.
4The ABS unit is fitted between the brake
master cylinder and the brakes, the vacuum
servo and master cylinder being of similar
type for both non-ABS and ABS models.
9•2Braking system

outboard pad and anti-squeal shim that fits
between the pad and the caliper body.
7Withdraw the inboard pad and anti-squeal
shim.
Refitting
8Proceed as described in Section 4,
paragraphs 10 and 11.
9Check that the cutaway recesses in the
pistons are positioned downwards, at
approximately 23°to the horizontal. A
template made of card may be used to check
the setting (see illustration). If necessary,
carefully turn the pistons to their correct
positions.
10Apply a little brake grease to the top and
bottom edges of the backplates on the new
brake pads.
11Locate the new pads and the anti-squeal
shims in the caliper. Ensure that the friction
material faces the disc, and check that the
pads are free to move slightly.
12Locate the anti-rattle spring on the pads,
then insert the pad retaining pins from the
inside edge of the caliper, while depressing
the spring. Tap the pins firmly into the caliper.
13Repeat the operations on the remaining
side of the vehicle.
14Proceed as described in Section 4,
paragraphs 17 to 20 inclusive.
6Rear brake shoes (drum
brakes) - inspection, removal
and refitting
3
Note: When working on the brake
components, take care not to disperse brake
dust into the air, or to inhale it, since it may
contain asbestos, which can damage your
health.
Inspection
1It is recommended that the brake shoes are
inspected when necessary by removing the
drums. This will enable a proper inspection of
the linings to be made, and additionally, the
wheel cylinders can be inspected for leaks. If
preferred, however, a provisional inspection of
the state of wear of the rear shoe linings can
be made by removing the plugs from the
inspection holes in the brake backplates.2Use a torch or inspection lamp, and if
necessary a mirror, to check that the friction
material has not worn down to less than the
specified minimum.
3If any one of the shoes has worn below the
specified limit, all four rear brake shoes must
be renewed as a set, as follows.
Removal
4Where applicable, remove the wheel trims,
then loosen the rear roadwheel bolts and
chock the front wheels. Jack up the rear of the
vehicle, and support on axle stands (see
“Jacking and Vehicle Support”) positioned
under the body side members. Remove the
roadwheels.
5Fully release the handbrake.
6Extract the drum securing screw and
remove the drum. If the drum is tight, remove
the plug from the inspection hole in the brake
backplate, and push the handbrake operating
lever towards the brake shoe to move the
shoes away from the drum. If necessary,
slacken the handbrake cable adjuster (see
illustrations).
7Note the location and orientation of all
components before dismantling, as an aid to
reassembly.
8Clean the dust and dirt from the drum and
shoes, but take care not to inhale it.
9Remove the shoe hold-down pins, springs
and cups by depressing the cups and turning
them through 90°using a pair of pliers (see
illustrations). Note that the hold-down pins
are removed through the rear of the brake
backplate.
10Disconnect the handbrake cable from the
operating lever.11The upper and lower return springs may
now be unhooked and the shoes removed
separately, or the assembly of shoes, adjuster
strut and springs may be removed together.
Remove the hub, refer to Chapter 10, if
necessary. Take care not to damage the
wheel cylinder rubber boots. Before removing
the return springs, note the position and
orientation of the springs and adjuster strut.
12If the shoes are to be removed for some
time, fit a stout rubber band or a spring clip to
the wheel cylinder, to prevent the pistons from
being pushed out of their bores. In any event,
do not press the brake pedal while the drum is
removed.
Refitting
13Clean the dust and dirt from the brake
backplate, but take care not to inhale it.
14Apply a small amount of brake grease to
the shoe rubbing areas on the backplate.
15Investigate and rectify any source of
contamination of the linings (wheel cylinder or
hub bearing oil seal leaking).
16Although linings are available separately
(without shoes), renewal of the shoes
complete with linings is to be preferred,
unless the reader has the necessary skills and
equipment to fit new linings to the old shoes.
17If not already done, dismantle the shoes,
strut and springs. Note the position and
orientation of the components. On later
models (1992-on), the brake shoe lower
anchorage has been modified so that it is now
rectangular, necessitating modified brake
shoes and a modified lower return spring (see
illustration).
9•6Braking system
5.9 Checking a rear caliper piston cut
away recess angle with a card template6.6B Push the handbrake operating lever
to move the shoes away from the drum
6.9B . . . then withdraw the cup and spring6.9A Release the shoe hold-down cup . . .
6.6A Extracting a brake drum securing
screw

18If both brake assemblies are dismantled
at the same time, take care not to mix up the
components. Note that the left-hand and
right-hand adjuster components are marked.
The threaded rod is marked “L” or “R”, and
the other “handed” components are colour-
coded black for the left-hand side, and silver
for the right-hand side.
19Dismantle and clean the adjuster strut.
Apply a smear of silicone-based grease to the
adjuster threads.
20Examine the return springs. If they are
distorted, or if they have seen extensiveservice, renewal is advisable. Weak springs
may cause the brakes to bind.
21If a new handbrake operating lever was
not supplied with the new shoes (where
applicable), transfer the lever from the old
shoes. The lever may be secured with a pin
and circlip, or by a rivet, which will have to be
drilled out.
22If the components are to be refitted as an
assembly, assemble the new shoes, springs
and adjuster components. Expand the
adjuster strut to ease fitting (see
illustrations).
23Offer the shoes to the brake backplate. Be
careful not to damage the wheel cylinder
boots, or to displace the pistons. Remember
to remove the rubber band or spring clip from
the wheel cylinder, where applicable.
24When the shoes are in position, insert the
hold-down pins and secure them with the
springs and cups (see illustration).
25Reconnect the handbrake cable, then refit
the hub, and adjust the bearing if the hub was
removed.
26Fitting the shoes and springs together as
an assembly may be too difficult. It is possible
to fit the shoes and secure them with the
hold-down pins and then fit the adjuster strut,
the return springs and adjuster.27Back off the adjuster wheel to reduce the
length of the strut, until the brake drum will
pass over the shoes.
28Make sure that the handbrake operating
lever is correctly positioned, with the pin on
the edge of the shoe web, not riding on top of
it, then refit and secure the brake drum.
29Repeat the operations on the remaining
side of the vehicle.
30Adjust the brakes by operating the
footbrake at least fifteen times. A clicking
noise will be heard at the drums, as the
automatic adjusters operate. When the
clicking stops, adjustment is complete.
31Check the handbrake adjustment, as
described in Section 26.
32Refit the roadwheels, and lower the
vehicle to the ground. Do not fully tighten the
roadwheel bolts until the vehicle is resting on
its wheels.
33New brake linings should be carefully
bedded-in and, where possible, heavy braking
should be avoided during the first 100 miles
(160 km) or so after fitting new linings.
7Handbrake shoes (rear disc
brakes) - inspection, removal
and refitting
3
Note: When working on the brake
components, take care not to disperse brake
dust into the air, or to inhale it, since it may
contain asbestos, which can damage your
health.
Inspection
1Although 2.0 litre models are fitted with rear
disc brakes, the handbrake operates
independently of the footbrake, using brake
shoes on the inside of the disc in a similar way
to rear drum brake models.
2To inspect the handbrake shoes on all
SOHC models, it is necessary to remove the
hub/disc, as described in Chapter 10.
3To inspect the handbrake shoes on DOHC
models it will be necessary to remove the
brake disc, as described in Section 10.
4With the hub/disc or the disc (as applicable)
removed, check that the friction material has
not worn down to less than the specified
minimum.
Braking system 9•7
6.22A Right-hand adjuster strut correctly
fitted to shoes
6.24 Rear brake components correctly
assembled (hub removed for clarity)6.22C Adjuster lever spring fitted to
leading shoe6.22B Fitting the upper return spring to
the shoes
6.17 Modified rear brake shoe lower anchorage - 1992-on models
9

5If any one of the shoes has worn below the
specified limit, all four handbrake shoes must
be renewed as a set, as follows.
SOHC models
Removal
6Clean the dust and dirt from the various
components, but take care not to inhale it.
7Disconnect the handbrake cable and the
return spring from the handbrake operating
lever at the brake backplate. If necessary,
slacken the handbrake cable adjustment, with
reference to Section 26.
8Remove the shoe hold-down pins, springs
and cups by depressing the cups and turning
them through 90°using a pair of pliers. Note
that the hold-down pins are removed through
the rear of the brake backplate.
9The shoes, adjuster, handbrake operating
lever and return springs can now be removed
together as an assembly.
10Note the position and orientation of all
components, then unhook the upper and
lower return springs from the shoes, and
recover the handbrake operating lever and the
adjuster.
Refitting
11Apply a little brake grease to the threads
of the adjuster, then screw it together to its
minimum length. Also apply a little brake
grease to the shoe rubbing areas on the
lockplate.
12Fit one of the new brake shoes, and
secure it to the backplate with the hold-down
pin, spring and cup.
13Fit the handbrake operating lever in
position.
14Fit the remaining brake shoe, and secure
with the hold-down pin, spring and cup.
15Hook the upper return spring onto the
shoes.
16Fit the adjuster between the lower ends of
the shoes, as noted before dismantling, then
fit the lower return spring (see illustrations).
17Reconnect the handbrake cable and the
return spring to the handbrake operating
lever.
18Refit the hub/disc, and adjust the wheel
bearing play, as described in Chapter 10, but
do not refit the roadwheel at this stage.
19Repeat the operations on the remaining
side of the vehicle.20Check the handbrake cable adjustment,
as described in Section 26.
21Refit the roadwheels and lower the vehicle
to the ground. Do not fully tighten the
roadwheel bolts until the vehicle is resting on
its wheels.
DOHC models
Removal
22Proceed as described in paragraphs 6
and 7.
23Remove the shoe hold-down pins, springs
and cups by turning the cups through using a
screwdriver. Note that the hold-down pins are
removed through the rear of the brake
backplate. Note also the position and
orientation of all components, then unhook
the upper and lower return springs from the
shoes, and recover the handbrake operating
lever and the adjuster.
Refitting
24Proceed as described in paragraphs 11 to
14 inclusive.
25Hook the lower return spring onto the
shoes.
26Fit the adjuster between the upper ends of
the shoes, as noted before dismantling, then
fit the upper return spring (see illustration).
27Reconnect the handbrake cable and the
return spring to the handbrake operating
lever.
28Refit the brake disc as described in
Section 10, but do not refit the roadwheel at
this stage.
29Proceed as described in paragraphs 19
to 21 inclusive.
8Front disc caliper - removal,
overhaul and refitting
3
Note: Refer to the note at the beginning of
Section 3 before proceeding. Before
dismantling a caliper, check that replacement
parts can be obtained, and retain the old
components to compare them with the new
ones. New sealing rings must be used on the
fluid hose union bolt on refitting
Models with solid discs
Removal
1Where applicable, remove the wheel trims,
then loosen the relevant front roadwheel bolts
and apply the handbrake. Jack up the front of
the vehicle, and support securely on axle
stands (see “Jacking and Vehicle Support”)
positioned under the body side members.
Remove the roadwheel.
2Remove the brake disc pads, as described
in Section 4.
3Working under the bonnet, remove the
brake fluid reservoir cap, and secure a piece
of polythene over the filler neck with a rubber
band, or by refitting the cap. This will reduce
the loss of fluid during the following
procedure.
4Unscrew the brake fluid hose union bolt
from the rear of the caliper, and disconnect
the hose. Recover the two sealing rings from
the union bolt (one either side of the hose end
fitting). Be prepared for fluid spillage, and plug
the open ends to prevent dirt ingress and
further fluid loss.
5Prise out the two caliper bracket mounting
bolt dust caps from the inboard edge of the
caliper bracket, then using an Allen key or
hexagon bit, unscrew the mounting bolts, and
withdraw the caliper assembly from the
vehicle.
Overhaul
6If desired, the caliper can be overhauled as
follows. Otherwise, go on to paragraph 24 for
details of refitting.
7Brush the dirt and dust from the caliper, but
take care not to inhale it.
8Mount the caliper bracket in a soft-jawed
vice. Then separate the caliper body from the
mounting bracket by pressing the front face of
the caliper body downwards and simultane-
ously sliding the caliper body from the
locating pins on the bracket. Recover the
guide springs from the bracket, noting their
orientation.
9Using a screwdriver, prise the dust seal
retaining clip from the piston dust seal, then
carefully prise off the dust seal.
10Place a thin piece of wood in front of the
piston to prevent it from falling out of its bore
and sustaining damage. Then apply low air
pressure - e.g. from a foot pump - to the
hydraulic fluid union hole in the rear of the
caliper body, to eject the piston from its bore.
9•8Braking system
7.16A Fitting the lower shoe return spring
- SOHC models
7.26 Handbrake shoe adjuster and upper
return spring correctly fitted - DOHC models
7.16B Handbrake shoe components
correctly assembled - SOHC models