OPEL CALIBRA 1988 Service Repair Manual

Overhaul
6If desired, the caliper can be overhauled as
follows. Otherwise, go on to paragraph 20 for
details of refitting.
7Brush the dirt and dust from the caliper, but
take care not to inhale it.
8Note that no attempt must be made to
separate the two halves of the caliper.
9Using a screwdriver, prise the dust seal
retaining clips from the piston dust seals, then
carefully prise off the dust seals.
10Using a clamp, secure one of the pistons
in its fully retracted position. 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 remaining piston
from its bore. Take care not to drop the
piston, which may result in damage.
11Temporarily close off the bore of the
removed piston, using a flat piece of wood or
similar improvised tool. Then remove the
clamp from the remaining piston, and again
apply air pressure to the caliper union to eject
the piston.
12Carefully prise the seals from the grooves
in the caliper piston bores, using a plastic or
wooden instrument.
13Inspect the surfaces of the pistons and
their bores in the caliper for scoring, or
evidence of metal-to-metal contact. If evident,
renew the complete caliper assembly.
14If the pistons and bores are in good
condition, discard the seals and obtain a
repair kit, which will contain all the necessary
renewable items. Also obtain a tube of brake
cylinder paste.
15Clean the piston and cylinder bore with
brake fluid or methylated spirit - nothing else!
16Apply a little brake cylinder paste to the
pistons, cylinder bores and piston seals.
17Begin reassembly by fitting the seals to
the grooves in the caliper bores.
18Locate the dust seals in their grooves in
the pistons, then insert the pistons carefully
into their bores until they enter the seals. It
may be necessary to rotate the pistons to
prevent them from jamming in the seals.
19When the pistons have been partially
depressed, engage the dust seals with the
rims of the caliper bores, and fit the retaining
clips.
Refitting
20Refit the caliper and tighten the securing
bolts to the specified torque, ensuring that the
ABS sensor bracket is in position, where
applicable.
21Reconnect the brake fluid pipe to the
caliper, and tighten the union nut.
22Refit the disc pads, as described in
Section 5.
23Remove the polythene from the brake
fluid reservoir filler neck and bleed the
relevant brake hydraulic circuit, as described
in Section 3.
24Refit the roadwheel and lower the vehicle
to the ground. Do not fully tighten the
roadwheel bolts until the vehicle is resting on
its wheels.
10Brake disc - inspection,
removal and refitting
3
Inspection
1Where applicable, remove the wheel trim,
then loosen the relevant roadwheel bolts. If
checking a front disc, apply the handbrake,
and if checking a rear disc, chock the front
wheels, then jack up the relevant end of the
vehicle and support on axle stands (see
“Jacking and Vehicle Support”) positioned
under the body side members. Remove the
roadwheel.
2Where applicable, check that the brake disc
securing screw is tight. Then fit a spacer
approximately 10.0 mm (0.4 in) thick to one of
the roadwheel bolts, and refit and tighten the
bolt in the hole opposite the disc securing
screw (see illustration).
3Rotate the brake disc, and examine it for
deep scoring or grooving. Light scoring is
normal, but if excessive, the disc should be
removed and either renewed or machined
(within the specified limits) by an engineering
works.
4Using a dial gauge, or a flat metal block and
feeler blades, check that the disc run-out does
not exceed the figure given in the Specifications.
Measure the run-out 10.0 mm (0.4 in) in from the
outer edge of the disc. 5On all SOHC models, if the rear disc run-
out is excessive, check the rear wheel bearing
adjustment, as described in Chapter 10.
6If the front disc run-out (all models), or the
rear disc run-out (DOHC models), is
excessive, remove the disc as described later
in this Section. Check that the disc-to-hub
surfaces are perfectly clean. Refit the disc and
check the run-out again.
7If the run-out is still excessive, the disc
should be renewed.
8To remove a disc, continue as follows.
Front disc
Removal
9Where applicable, remove the roadwheel
bolt and spacer used when checking the disc.
10Remove the disc pads, (Section 4).
11On 2.0 litre models, unscrew the two
securing bolts and remove the caliper
bracket.
12Remove the securing screw and withdraw
the disc from the hub, where applicable tilting
it to clear the brake caliper (see illustration).
Refitting
13Refitting is a reversal of removal, but
make sure that the mating faces of the disc
and hub are perfectly clean, and apply a little
locking fluid to the threads of the securing
screw. Refit the disc pads, (Section 4).
Rear disc - SOHC models
14On these models, the disc is integral with
the rear hub, and removal and refitting is
described in Chapter 10.
9•10Braking system
9.5A Withdrawing a rear caliper mounting
bolt . . .10.2 Refit a wheel bolt and spacer
(arrowed) opposite the disc securing screw
(A) before checking brake disc run-out
10.12 Removing a disc securing screw -
SOHC model
9.5B . . . which also secures the ABS
sensor bracket - DOHC model

Rear disc - DOHC models
Removal
15Where applicable, remove the roadwheel
bolt and spacer used when checking the disc.
16Remove the disc pads, as described in
Section 5.
17Remove the brake caliper with reference
to Section 9, but leave the hydraulic fluid pipe
connected. Move the caliper to one side, and
suspend it using wire or string to avoid
straining the pipe.
18Remove the securing screw and withdraw
the disc from the hub (see illustration). If the
disc is tight, collapse the handbrake shoes by
inserting a screwdriver through the adjuster
hole in the disc and turning the adjuster
wheel.
Refitting
19Refitting is a reversal of removal, but
make sure that the mating faces of the disc
and hub are perfectly clean, and apply a little
locking fluid to the threads of the securing
screw. Refit the disc pads, as described in
Section 5.
11Brake drum - removal,
inspection 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.
Removal
1Where applicable, remove the wheel trim,
then loosen the relevant 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 roadwheel.
2Fully release the handbrake.
3Extract 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 theshoes away from the drums. If necessary,
slacken the handbrake cable adjuster.
Inspection
4Brush the dirt and dust from the drum,
taking care not to inhale it.
5Examine the internal friction surface of the
drum. If they are deeply scored, or so worn
that the drum has become ridged to the width
of the shoes, then both drums must be
renewed.
6Regrinding of the friction surface is not
recommended, since the internal diameter of
the drum will no longer be compatible with the
shoe friction material contact diameter.
Refitting
7Refit the brake drum and tighten the
securing screw. If necessary, back off the
adjuster wheel until the drum will pass over
the shoes.
8Adjust the brakes by operating the
footbrake a number of times. A clicking noise
will be heard at the drum as the automatic
adjuster operates. When the clicking stops,
adjustment is complete.
9Refit the roadwheel and lower the vehicle to
the ground. Do not fully tighten the roadwheel
bolts until the vehicle is resting on its wheels.
12Rear wheel cylinder (drum
brakes) - removal, overhaul
and refitting
3
Note: Refer to the notes at the beginning of
Sections 3 and 11 before proceeding. Before
dismantling a wheel cylinder, check that
replacement parts can be obtained, and retain
the old components to compare them with the
new ones
Removal
1Where applicable, remove the wheel trim,
then loosen the relevant 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
roadwheel.
2Fully release the handbrake.3Extract 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.
4Using a pair of pliers, unhook the upper
return spring from the brake shoes, noting its
orientation, then push the upper ends of the
shoes apart until they are clear of the wheel
cylinder (see illustration).
5Working 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.
6Unscrew the brake fluid pipe union nut from
the rear of the wheel cylinder, and disconnect
the pipe (see illustration). Take care not to
strain the pipe. Be prepared for fluid spillage,
and plug the open ends to prevent dirt ingress
and further fluid loss.
7Unscrew the two securing bolts from the
rear of the brake backplate, and withdraw the
wheel cylinder.
Overhaul
8If desired, the wheel cylinder can be
overhauled as follows. Otherwise, go on to
paragraph 17 for details of refitting.
9Brush the dirt and dust from the wheel
cylinder, but take care not to inhale it.
10Pull the rubber dust seals from the ends of
the cylinder body.
11The pistons will normally be ejected by
the pressure of the coil spring. If they are not,
tap the end of the cylinder body on a piece of
wood, or apply low air pressure (e.g. from a
foot pump), to the hydraulic fluid union hole in
the rear of the cylinder body, to eject the
pistons from their bores.
12Inspect the surfaces of the pistons and
their bores in the cylinder body for scoring, or
evidence of metal-to-metal contact. If evident,
renew the complete wheel cylinder assembly.
Note that the later type of wheel cylinder can
be used to replace the early type as a
complete unit.
Braking system 9•11
12.6 Unscrewing rear wheel cylinder brake
fluid pipe union12.4 Rear brake assembly
1 Wheel cylinder
2 Upper shoe return spring (note
orientation)
10.18 Withdrawing the rear brake disc -
DOHC model
9

13If the pistons and bores are in good
condition, discard the seals and obtain a
repair kit, which will contain all the necessary
renewable items. Later models (1992-on), are
fitted with L-shaped piston seals (see
illustrations). Ensure that the correct repair
kit is obtained when overhauling a wheel
cylinder, as the early and later components
are not interchangeable.
14Lubricate the piston seals with clean
brake fluid, and insert them into the cylinder
bores with the spring between them, using
finger pressure only.
15Dip the pistons in clean brake fluid, and
insert them into the cylinder bores.
16Fit the dust seals, and check that the
pistons can move freely in their bores.
Refitting
17Refit the wheel cylinder to the backplate,
and tighten the securing bolts.
18Reconnect the brake fluid pipe to the
cylinder, and tighten the union nut.
19Push the brake shoes against the pistons,
then refit the upper return spring as noted
before removal.
20Refit the brake drum and tighten the
securing screw. If necessary, back off the
adjuster wheel until the drum will pass over
the shoes.
21Remove the polythene from the brake
fluid reservoir filler neck, and bleed the
relevant brake hydraulic circuit, as described
in Section 3.
22Adjust the brakes by operating the
footbrake a number of times. A clicking noise
will be heard at the drum as the automatic
adjuster operates. When the clicking stops,
adjustment is complete.
23Refit the roadwheel and lower the vehicle
to the ground. Do not fully tighten the
roadwheel bolts until the vehicle is resting on
its wheels.
13Rear brake backplate -
removal and refitting
3
Models with rear drum brakes
Removal
1Where applicable, remove the wheel trim,
then loosen the relevant 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 roadwheel.
2Remove the brake drum with reference to
Section 11.
3Remove the rear hub, (Chapter 10).
4Remove the brake shoes, (Section 6).
5Remove the brake wheel cylinder, as
described in Section 12.
6Using a screwdriver, prise out the lockplate
that secures the handbrake cable in the
backplate.
7Unscrew the four securing bolts, and
withdraw the stub axle and backplate.
Refitting
8Refitting is a reversal of removal,
remembering the following points.
9Coat the rear face of the stub axle flange
with a little lithium-based grease.
10Tighten the brake backplate/stub axle
securing bolts to the specified torque, in the
three stages given in the Specifications.
11Refit the brake wheel cylinder, as
described in Section 12.
12Refit the brake shoes, as described in
Section 6.
13Refit the rear hub, as described in
Chapter 10.
14Refit the brake drum with reference to
Section 11.
15Before refitting the roadwheel and
lowering the vehicle to the ground, check and
if necessary adjust the handbrake, as
described in Section 26.
Models with rear disc brakes
(SOHC models)
Removal
16Proceed as described in paragraphs 1
to 7.
17Remove the rear hub/disc, (Chapter 10).
18Remove the handbrake shoes, (Section 7).
19Unscrew the four securing bolts, and
withdraw the stub axle and lockplate.
Refitting
20Refitting is a reversal of removal,
remembering the following points.
21Coat the rear face of the stub axle flange
with a little lithium-based grease.
22Tighten the brake backplate/stub axle
securing bolts to the specified torque, in the
three stages given in the Specifications.
23Refit the handbrake shoes, as described
in Section 7.
24Refit the rear hub/disc, (Chapter 10).
25Before refitting the roadwheel and
lowering the vehicle to the ground, check and
if necessary adjust the handbrake, as
described in Section 26.
DOHC models
Removal
26Proceed as described in paragraphs 1
to 7.
27Remove the brake disc (Section 10).
28Remove the rear hub, (Chapter 10).
29Remove the handbrake shoes, (Section 7).
30Using a splined key, unscrew the four
securing bolts and withdraw the backplate.
Refitting
31Refitting is a reversal of removal,
remembering the following points.
32Refit the handbrake shoes, (Section 7).
33Refit the rear hub, (Chapter 10).
34Refit the brake disc (Section 10).
35Before refitting the roadwheel and
lowering the vehicle to the ground, check and
if necessary adjust the handbrake, as
described in Section 26.
9•12Braking system
12.13A Exploded view of a rear brake
wheel cylinder
1 Dust cap
2 Bleed screw
3 Cylinder body
4 Dust seal5 Piston
6 Piston seal
7 Spring
12.13B Modified rear wheel cylinders - 1992-on models

14Front brake disc shield -
removal and refitting
3
Removal
1Where applicable, remove the wheel trim,
then loosen the relevant front roadwheel bolts
and apply the handbrake. Jack up the front of
the vehicle, and support on axle stands (see
“Jacking and Vehicle Support”) positioned
under the body side members. Remove the
roadwheel.
2Remove the brake disc, as described in
Section 10.
3Using a screwdriver inserted through the
holes in the hub flange, extract the three
screws securing the disc shield to the hub
carrier.
4Using plate shears or an alternative tool, cut
a section of metal from the rear edge of the
shield to enable the shield to be withdrawn
over the hub, then remove the shield (see
illustration).
Refitting
5If a new shield is to be fitted, cut out a
section of metal, as during removal of the old
shield, to enable the shield to be fitted.
Smooth the cut edges, and coat them with
anti-corrosion paint.
6Further refitting is a reversal of removal,
remembering the following points.
7Refit the brake disc, as described in
Section 10.
8Do not fully tighten the roadwheel bolts until
the vehicle is resting on its wheels.
15Master cylinder - removal and
refitting
4
Note: Refer to the note at the beginning of
Section 3 before proceeding
Removal
1Disconnect the battery negative lead.
2Depress the footbrake pedal several times
to dissipate the vacuum in the servo unit.3Disconnect the wiring plug from the brake
fluid level sensor in the reservoir filler cap.
4If possible, use a teat pipette or an old
hydrometer to remove the brake fluid from the
reservoir. This will reduce the loss of fluid later
in the procedure.
5Locate a container beneath the master
cylinder, to catch the brake fluid that will be
released.
6Identify the brake fluid pipes for position,
then unscrew the union nuts and disconnect
the pipes from the master cylinder.
7Unscrew the two securing nuts, and
withdraw the master cylinder from the studs
on the vacuum servo unit (see illustration).
8Clean the external surfaces of the cylinder,
then using a screwdriver carefully prise the
fluid reservoir and its seals from the top of the
cylinder.
9If desired, on models without ABS, the
master cylinder can be overhauled, as
described in Section 16.
10No overhaul of the master cylinder is
possible on models with ABS, see Section 17.
Refitting
11Refitting is a reversal of removal, but use
new seals when fitting the brake fluid
reservoir, and on completion, bleed the
complete brake hydraulic system, as
described in Section 3.
16Master cylinder (non-ABS) -
overhaul
4
Note: Before dismantling the master cylinder,
check that replacement parts can be obtained
and retain the old components to compare
them with the new ones
1With the master cylinder removed as
described in Section 15, continue as follows,
according to type.
GMF type master cylinder
2Clamp the master cylinder in a soft-jawed
vice.
3Where applicable, unscrew the pressure-
proportioning valves from the base of the
cylinder.4Carefully prise out the sealing ring from the
end of the cylinder bore.
5Depress the primary piston slightly using a
piece of wood or plastic. Then hold the piston
in the depressed position by inserting a
smooth pin or rod of 3.0 mm (0.12 in) diameter
through the primary fluid reservoir port in the
cylinder (see illustration).
6Extract the circlip from the end of the
cylinder bore using a screwdriver. Take care
not to damage the piston or cylinder bore.
7Withdraw the pin or rod retaining the piston.
8Withdraw the primary piston assembly from
the cylinder, if necessary tapping the cylinder
on a wooden block to free the piston from the
bore.
9Apply low air pressure - e.g. from a foot
pump - to the front fluid reservoir port in the
cylinder, to eject the secondary piston
assembly.
10Clean all the components, in clean brake
fluid or methylated spirit only, and examine
them for wear and damage. In particular,
check the surfaces of the pistons and cylinder
bore for scoring and corrosion. If the bore
shows signs of wear, renew the complete
master cylinder assembly (see illustration).
11If the cylinder bore is in good condition,
obtain a repair kit, which will contain all the
necessary renewable items. A Vauxhall dealer
will supply a pre-assembled kit of parts, which
should be fitted as follows.
12Lubricate the cylinder bore with clean
brake fluid or brake grease, then clamp the
cylinder in a soft-jawed vice, with the bore
horizontal.
13Remove the plug from the end of the
assembly tube, and insert the short part of the
tube into the cylinder bore as far as the
shoulder on the tube.
14Use a piece of wood or plastic to push the
components out of the tube and into the
cylinder bore. Then hold the primary piston in
the depressed position by inserting the pin or
rod used during dismantling through the
cylinder primary fluid reservoir port.
15Fit a new circlip to the end of the cylinder
bore, ensuring that it seats correctly, and that
the piston is free to move.
16Depress the primary piston, and withdraw
the pin or rod from the fluid reservoir port.
Braking system 9•13
16.5 Holding the primary piston depressed
while extracting the circlip from the
cylinder body - GMF type master cylinder15.7 Master cylinder securing nut
(arrowed)14.4 Cutting a section of metal from a new
front brake disc shield prior to fitting
9

17Fit a new sealing ring to the end of the
cylinder bore.
18Where applicable, screw the pressure-
proportioning valves into the base of the
cylinder.
19Refit the master cylinder, as described in
Section 15.
ATE type master cylinder
20Clamp the master cylinder in a soft-jawed
vice.
21Where applicable, unscrew the pressure-
proportioning valves from the base of the
cylinder.
22Carefully prise out the sealing ring from
the end of the cylinder bore.
23Depress the primary piston slightly using
a piece of wood or plastic, then extract the
circlip from the end of the cylinder bore.
24Withdraw the primary piston assembly,
noting the location of the stop washers.
25Depress the secondary piston, again
using a piece of wood or plastic, and
withdraw the stop screw from the cylinder
body (see illustration).
26Withdraw the secondary piston assembly
from the cylinder, if necessary tapping the
cylinder on a wooden block to free the piston
from the bore.
27Clean all the components, in clean brake
fluid or methylated spirit only, and examine
them for wear and damage. In particular,
check the surfaces of the pistons and cylinder
bores for scoring and corrosion. If the bore
shows signs of wear, renew the complete
master cylinder assembly (see illustration).28If the cylinder bore is in good condition,
obtain a repair kit, which will contain all the
necessary renewable items. A Vauxhall dealer
will supply a complete kit of parts, which
should be fitted as follows.
29Lubricate the cylinder bore with clean
brake fluid or brake grease, then clamp the
cylinder in a soft-jawed vice, with the bore
horizontal.
30Fit a new sealing ring to the stop screw,
then screw it into the cylinder body a little
way, but not so far that it protrudes into the
bore.
31Remove the plugs from the ends of the
assembly tube, then remove all the
components from the short part of the tube,
and push the short part into the long part until
they are flush.
32Insert the assembly tube into the cylinder
bore as far as the collar on the short sleeve.
Then use a piece of wood or plastic to push
the secondary piston assembly into the bore
until it contacts the end of the cylinder.
33Lightly tighten the stop screw, then
withdraw the piece of wood or plastic and the
assembly tube, and fully tighten the stop
screw.
34Reposition the master cylinder in the vice,
with the bore facing upwards.
35Smear the primary piston skirt and the
seal grooves with the special grease provided
in the repair kit. Fit the stop washer to the
piston.
36Adjust the assembly tube so that the end
of the long part is flush with the inner shoulder
of the short part.37Fit the front seal to the primary piston,
with the open end of the seal facing the front
of the master cylinder.
38Place the assembly tube over the cylinder
to compress the seal, insert the piston and
tube part way into the bore, and withdraw the
tube.
39Place the intermediate ring on the primary
piston, then fit the remaining seal using the
assembly tube as described previously.
40Place the stop washer as the primary
piston, then depress the piston slightly using
a piece of wood or plastic, and fit a new circlip
to the end of the cylinder bore. Ensure that the
circlip is correctly seated, and that the piston
is free to move.
41Fit a new sealing ring to the end of the
cylinder bore.
9•14Braking system
16.25 Depressing the secondary piston
while extracting the stop screw - ATE type
master cylinder
16.27 Exploded view of ATE type master
cylinder
1 Filler cap (standard)
2 Strainer
3 Filler cap (with fluid level sensor)
4 Guide sleeve for float
5 Fluid reservoir
6 Cylinder body
7 Sealing ring
8 Fluid reservoir seals
9 Stop screw
10 Repair kit assembly tube
11 Pressure-proportioning valves
16.10 Exploded view of GMF type master
cylinder
1 Filler cap (standard)
2 Filler cap (with fluid level sensor)
3 Fluid reservoir
4 Fluid reservoir retaining clips
5 Fluid reservoir seals
6 Cylinder body
7 Secondary piston and springs
8 Primary piston
9 Circlip
10 Sealing ring
11 Pressure-proportioning valves

42Where applicable, screw the pressure-
proportioning valves into the base of the
cylinder.
43Refit the master cylinder, as described in
Section 15.
17Master cylinder (ABS) -
general
The master cylinder fitted to models with
ABS cannot be dismantled, and no attempt
should be made at overhaul.
If faulty, the complete unit must be
renewed, as described in Section 15.
18Vacuum servo - description
and testing
Description
1The vacuum servo is fitted between the
brake pedal and the master cylinder, and
provides assistance to the driver when the
pedal is depressed, reducing the effort required
to operate the brakes. The unit is operated by
vacuum from the inlet manifold. With the brake
pedal released, vacuum is channelled to both
sides of the internal diaphragm. However,
when the pedal is depressed, one side of the
diaphragm is opened to atmosphere, resulting
in assistance to the pedal effort. Should the
vacuum servo develop a fault, the hydraulic
system is not affected, but greater effort will be
required at the pedal.
Testing
2The operation of the servo can be checked
as follows.
3With the engine stopped, destroy the
vacuum in the servo by depressing the brake
pedal several times.
4Hold the brake pedal depressed and start
the engine. The pedal should sink slightly as
the engine is started.
5If the pedal does not sink, check the servo
vacuum hose for leaks.
6If no defects are found in the vacuum hose,
the fault must lie in the servo itself.7No overhaul of the servo is possible, and if
faulty, the complete unit must be renewed.
19Vacuum servo - removal and
refitting
4
Note: During the 1989 model year, some
vehicles were produced with the brake pedal
height incorrectly set, resulting in the brake
pedal resting approximately 15.0 mm (0.6 in)
above the clutch pedal instead of 4.0 mm
(0.16 in below). The correct pedal height can
be set by adjusting the vacuum servo
operating fork dimension, as described in
paragraphs 15 and 16
Removal
1Disconnect the battery negative lead.
2Working inside the vehicle, remove the
lower trim panel from the driver’s footwell.
3Disconnect the wiring plug from the brake
lamp switch, then twist the switch anti-
clockwise and remove it from its bracket.
4Pull the spring clip from the right-hand end
of the servo fork-to-pedal pivot pin.
5Using a pair of pliers, pull back the end of
the pedal return spring from the pedal, to
enable the servo fork-to-pedal pivot pin to be
removed. Withdraw the pivot pin.
6Remove the windscreen cowl panel, as
described in Chapter 11, then remove the
windscreen wiper motor and linkage as
described in Chapter 12.7Remove the coolant expansion tank as
described in Chapter 3.
8Pull the vacuum pipe from the brake servo.
9Unscrew the two securing nuts, and
carefully withdraw the brake master cylinder
from the studs on the servo. Move the master
cylinder forwards slightly, taking care not to
strain the brake pipes.
10Remove the two plugs covering the servo
securing bolts from the cowl panel (see
illustrations).
11Using a Allen key or hexagon bit, unscrew
the servo securing bolts and remove them
completely, then lift the servo from the
bulkhead (see illustrations).
12If desired, the mounting bracket can be
removed from the servo by unscrewing the
four securing nuts. Note that the bracket will
stick to the servo, as it is fitted with sealing
compound.
13The servo cannot be overhauled, and if
faulty, the complete unit must be renewed.
Refitting
14Before refitting the servo, check that the
operating fork dimension is correct as follows.
15Measure the distance from the end face of
the servo casing to the centre of the pivot pin
hole in the end of the operating fork. The
distance should be 144.0 mm (5.6 in). To
make accurate measurement easier, insert a
bolt or bar of similar diameter through the
pivot pin hole, and measure to the centre of
the bolt or bar (see illustration).
Braking system 9•15
19.11A Unscrew the securing bolts . . .19.15 Measuring the servo operating fork
dimension using a bolt inserted through
the pivot pin hole19.11B . . . and withdraw the servo
19.10B . . . to expose the servo securing
bolts19.10A Remove the plugs . . .
9

16If adjustment is necessary, slacken the
locknut, turn the fork to give the specified
dimension, then tighten the locknut.
17Where applicable, coat the contact faces
of the servo and the mounting bracket with
sealing compound, then refit the bracket to
the servo, and tighten the securing nuts to the
specified torque.
18Coat the threads of the servo securing
bolts with locking fluid, then fit the servo to
the bulkhead and tighten the securing bolts.
19Refit the securing bolt cover plugs to the
cowl panel.
20Refit the master cylinder to the servo, and
tighten the securing nuts to the specified
torque.
21Reconnect the vacuum pipe to the servo.
22Refit the coolant expansion tank, as
described in Chapter 3.
23Refit the windscreen wiper motor and
linkage as described in Chapter 12, then refit
the windscreen cowl panel.
24Further refitting is a reversal of removal.
On completion, test the operation of the
servo, as described in Section 18.
20ABS hydraulic modulator -
removal and refitting
4
Note: Refer to Section 2, and the note at the
beginning of Section 3, before proceeding
Removal
1Disconnect the battery negative lead.
2Remove 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.
3Remove the securing screw, and withdraw
the plastic cover from the hydraulic
modulator.
4Remove the two clamp screws, and lift off
the modulator wiring harness clamp (see
illustration).
5Disconnect the modulator wiring plug,
levering it from the socket with a screwdriver if
necessary.6Unscrew the brake fluid pipe union nuts,
and disconnect the pipes from the modulator.
Be prepared for fluid spillage, and plug the
open ends to prevent dirt ingress and further
fluid loss. Move the pipes just clear of the
modulator, taking care not to strain them.
7Unscrew the three modulator securing nuts
(see illustration), then tilt the modulator
slightly, and withdraw it upwards from its
bracket, sufficiently to gain access to the
earth lead securing nut at the front lower edge
of the modulator.
8Unscrew the securing nut and disconnect
the earth lead, then withdraw the modulator
from the vehicle, taking care not to spill brake
fluid on the vehicle paintwork.
9If a new modulator is to be fitted, pull the
two relays from the top of the old modulator,
and transfer them to the new unit. No attempt
must be made to dismantle the modulator.
Refitting
10Before refitting the modulator, check that
the bolts securing the mounting bracket to the
body panel are tight, and that the modulator
rubber mountings are in good condition.
Renew the rubber mountings if necessary.
11Refitting is a reversal of removal,
remembering the following points.
12Make sure that the earth lead is
reconnected before fitting the modulator to its
mounting bracket.13On completion, remove the polythene
sheet from the brake fluid reservoir filler neck,
and bleed the complete brake hydraulic
system, as described in Section 3.
14Check that the ABS warning lamp
extinguishes when first starting the engine
after the modulator has been removed. At the
earliest opportunity, take the vehicle to a
Vauxhall dealer, and have the complete
system tested, using the dedicated ABS test
equipment.
21ABS wheel sensors - removal
and refitting
3
Note: Refer to Section 2 before proceeding
Front wheel sensor
Removal
1Disconnect the battery negative lead.
2Where applicable, remove the wheel trim,
then loosen the relevant front roadwheel bolts
and apply the handbrake. Jack up the front of
the vehicle, and support on axle stands (see
“Jacking and Vehicle Support”) positioned
under the body side members. Remove the
roadwheel.
3Unclip the sensor wiring connector from the
retaining clip under the wheel arch, then
separate the two halves of the wiring
connector, prising them apart with a
screwdriver if necessary (see illustration).
4Using a Allen key or hexagon bit, unscrew
the bolt securing the wheel sensor to its
mounting bracket, then carefully lever the
sensor from the bracket using a screwdriver
(see illustration). Recover the seal ring.
Refitting
5Examine the condition of the seal ring, and
renew if necessary.
6Refitting is a reversal of removal,
remembering the following points.
7Smear a little grease on the sensor casing
before fitting it to the bracket.
8Do not fully tighten the roadwheel bolts until
the vehicle is resting on its wheels.
9Check that the ABS warning lamp
extinguishes when first starting the engine
after a wheel sensor has been removed. At
9•16Braking system
20.4 ABS hydraulic modulator (cover
removed)
1 Wiring harness
clamp screws2 Earth lead
3 Relays
21.3 Front wheel sensor wiring under
wheelarch - DOHC model
1 ABS sensor connector
2 Disc pad wear sensor wiring connector
21.4 ABS front wheel sensor securing bolt
(arrowed) - DOHC model20.7 ABS hydraulic modulator securing
screws (arrowed)

the earliest opportunity, take the vehicle to a
Vauxhall dealer, and have the complete
system tested, using the dedicated ABS test
equipment.
Rear wheel sensor
Removal
10Disconnect the battery negative lead.
11Where applicable, remove the wheel trim,
then loosen the relevant 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 roadwheel.
12Unclip the sensor wiring connector from
the retaining clip on the rear underbody, then
separate the two halves of the wiring
connector, prising them apart with a
screwdriver if necessary (see illustration).
13Note the routing of the sensor wiring, and,
where applicable, release it from the clips on
the underbody.
14Using a Allen key or hexagon bit, unscrew
the bolt securing the wheel sensor to the
trailing arm (or the mounting bracket on
DOHC models), then carefully lever the sensor
from its location using a screwdriver (see
illustration). Recover the seal ring.
Refitting
15Proceed as described in paragraphs 5 to 9
inclusive.
22ABS electronic control
module - removal and refitting
3
Note: Refer to Section 2 before proceeding
ABS-2E systems
Removal
1Ensure that the ignition is switched off, then
disconnect the battery negative lead.
2The control module is located under a
cover in the passenger sill, to the left-hand
side of the seat.
3Extract the three securing screws, and lift
the cover from the control module. Note that
two of the screws are covered by plastic trim
plugs. 4Lift the control module from its recess, then
release the retaining clip and disconnect the
module wiring plug. Withdraw the module
(see illustrations).
Refitting
5Refitting is a reversal of removal.
6Check that the ABS warning lamp
extinguishes when first starting the engine
after the module has been removed. At the
earliest opportunity, take the vehicle to a
Vauxhall dealer, and have the complete
system tested, using the dedicated ABS test
equipment.
ABS-2EH systems
Removal
7Ensure that the ignition is switched off, then
disconnect the battery negative lead.
8Remove the cover from the hydraulic
modulator.
9Disconnect both the wiring harness and
solenoid valve connectors.
10Relays can only be removed from control
units that have slanted covers (see
illustration). The relays for the solenoid valve
and pump motor, if removable, can now be
removed. If the unit has a flat cover, and is
faulty, the whole unit will have to be replaced.
11Undo fixing bolts and remove the control
unit.
Refitting
12Refitting is a reversal of removal. Refer
also to paragraph 6.
23ABS relays (ABS-2E systems
only) - removal and refitting
2
Note: Refer to Section 2 before proceeding.
For ABS-2EH system relays, refer to
paragraphs 7 to 12, in Section 22.
Solenoid valve and pump motor
relays
Removal
1The solenoid valve and pump motor relays
are mounted on the hydraulic modulator.
2Disconnect the battery negative lead.
3Remove the securing screw and withdraw
the plastic cover from the hydraulic
modulator.
4Pull out the appropriate relay. The small
relay is for the solenoid valve, and the large
relay is for the pump motor.
Refitting
5Refitting is a reversal of removal.
6Check that the ABS warning lamp
extinguishes when first starting the engine
after a relay has been removed. At the earliest
opportunity, take the vehicle to a Vauxhall
dealer, and have the complete system tested,
using the dedicated ABS test equipment.
Surge arrester relay
Removal
7The surge arrester relay is located in the
relay box at the left rear of the engine
compartment.
Braking system 9•17
22.4A Lift out the ABS control module . . .22.10 ABS-2EH control unit
1 Slanted cover type 2 Flat cover type22.4B . . . and release the wiring plug
retaining clip - ABS-2E system
21.14 ABS rear wheel sensor (arrowed) -
DOHC model21.12 ABS rear wheel sensor wiring
connectors (arrowed) on rear underbody -
DOHC model`
9

8Disconnect the battery negative lead.
9Unclip the lid and open the relay box, then
pull out the relay (see illustration).
Refitting
10Refitting is a reversal of removal, with
reference to paragraph 6.
24Rear brake pressure-
proportioning valves -
removal and refitting
4
Note: Refer to the note at the beginning of
Section 3 before proceeding. Note also that
the valve must only be renewed in pairs, and
both valves must be of the same calibration.
Ensure that correct type of valves are fitted.
The bodies have been stamped for easier
identification.
Master cylinder-mounted valves
Removal
1Remove 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.
2Locate a container beneath the master
cylinder, to catch the brake fluid that will be
released.
3Identify the two lower brake pipes for
position, then unscrew the union nuts and
disconnect the pipes from the proportioning
valves in the base of the master cylinder. Plug
the open ends of the pipes to prevent dirt
ingress.
4Unscrew the proportioning valves from the
master cylinder, and plug the open ends of
the cylinder to prevent dirt ingress.
Refitting
5Refitting is a reversal of removal, but on
completion, remove the polythene from the
brake fluid reservoir filler neck, and bleed the
complete hydraulic system, as described in
Section 3.
Rear underbody-mounted valves
Removal
6Proceed as described in paragraph 1.
7Chock the front wheels, then jack up the
rear of the vehicle, and support securely on
axle stands (see “Jacking and Vehicle
Support”) positioned under the body side
members.
8Working under the rear of the vehicle,
unscrew the union nut and disconnect the
brake pipe from one of the valves. Be
prepared for fluid spillage, and plug the open
end of the pipe to prevent dirt ingress and
further fluid spillage.
9Similarly, disconnect the flexible hose from
the valve.
10Pull the valve retaining clip from the
bracket on the underbody, noting that on
certain models, the retaining clip also secures
the ABS sensor wiring, and withdraw the valve
(see illustration).
11Repeat the procedure for the other valve.
Refitting
12Proceed as described in paragraph 5.
25Brake fluid pipes and hoses
- general, removal and refitting
4
Note: Refer to the note at the beginning of
Section 3, before proceeding.
General
1When checking the condition of the
system’s pipes and/or hoses, carefully check
that they do not foul other components such
as the power steering gear pipes (where
applicable), so that there is no risk of the
pipes chafing. If necessary use clips or ties to
secure braking system pipes and hoses well
clear of other components.
Rigid pipes
Removal
2Some of the commonly used brake pipes
can be obtained from Vauxhall parts dealers,
ready-formed and complete with unions, but
other brake pipes must be prepared using
4.75 mm (0.19 in) diameter brake pipe. Kits for
making the brake pipes can be obtained from
certain motor accessory shops.
3Before removing a brake pipe, 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 when the pipe is
disconnected.4Jack up the vehicle, and support securely
on axle stands (see “Jacking and Vehicle
Support”) positioned under the body side
members.
5To remove a brake pipe, unscrew the
unions at each end, and release the pipe from
the retaining clips.
Refitting
6Refitting is a reversal of removal, taking
care not to overtighten the unions.
7On completion, remove the polythene from
the brake fluid reservoir filler neck, and bleed
the relevant hydraulic circuit(s), as described
in Section 3.
Flexible hoses
Removal
8Proceed as described previously for the
rigid pipes, but note that a flexible pipe must
never be installed twisted, although a slight
“set” is permissible to give it clearance from
adjacent components.
Refitting
9When reconnecting a flexible hose to a
front brake caliper, note that the sealing rings
on the union bolt must be renewed.
26Handbrake - adjustment
2
Models with rear drum brakes
1The handbrake will normally be kept in
correct adjustment by the self-adjusting
action of the rear brake shoes. However, due
to cable stretch over a period of time, the
travel of the handbrake lever may become
excessive, in which case the following
operations should be carried out.
2Chock the front wheels, jack up the rear of
the vehicle, and support securely on axle
stands (see “Jacking and Vehicle Support”)
positioned under the body side members.
3Fully release the handbrake.
4Turn the knurled nut on the cable adjuster
(mounted on the torsion beam), until the brake
shoes can just be heard to rub when the rear
wheels are turned by hand in the normal
direction of rotation (see illustration).
9•18Braking system
23.9 ABS surge arrester relay (arrowed)
26.4 Handbrake cable adjuster. Knurled
nut arrowed - all SOHC models24.10 Brake pressure-proportioning valve
on rear underbody - DOHC model
1 Valve 2 Retaining clip

5Loosen the adjuster nut until the wheels are
just free to turn.
6The handbrake must start to operate with
the lever on the second notch of the ratchet.
7On completion of adjustment, check the
handbrake cables for free movement, and
apply a little grease to the adjuster threads to
prevent corrosion.
8Lower the vehicle to the ground.
Models with rear disc brakes
9Where 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 securely on axle stands
(see “Jacking and Vehicle Support”)
positioned under the body side members.
Remove the roadwheels.
10Pull the handbrake lever as far as the
second notch on the ratchet.
11On DOHC models fitted with a catalytic
converter, unscrew the four securing nuts and
withdraw the exhaust centre box heat shield
by carefully sliding it round the centre box.
12On all SOHC models, loosen the knurled
nut on the cable adjuster (mounted on the
torsion beam).
13On DOHC models, loosen the nut
securing the cable equaliser yoke to the
handbrake lever operating rod.
14Using a screwdriver inserted through the
adjuster hole in one of the discs/hubs (see
illustration), turn the adjuster wheel until the
brake shoes can just be heard to rub when the
disc/hub is turned by hand in the normal
direction of rotation.
15Turn the adjuster wheel back until the
disc/hub is just free to turn.
16Repeat paragraphs 14 and 15 on the
remaining side of the vehicle.
17Tighten the nut on the cable adjuster or
the equaliser, as applicable, until the brakeshoes just begin to operate. Check that the
shoes operate equally on both wheels.
18Fully release the handbrake, then apply it
again.
19The discs/hubs must lock when the
handbrake lever reaches the sixth notch on
the ratchet. If necessary, turn the nut on the
cable adjuster or equaliser, as applicable, to
achieve this.
20Where applicable, refit the exhaust heat
shield.
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.
27Handbrake cable - removal
and refitting
3
Models with rear drum brakes
Removal
1The handbrake cable is in two sections. The
longer section runs from the handbrake
operating rod, through the adjuster, to the
right-hand brake assembly. The shorter
section runs from the adjuster to the left-hand
brake assembly. The two sections of the cable
can be renewed independently.
2Where applicable, remove the wheel trim(s),
then loosen the relevant rear roadwheel bolts.
Chock the front wheels, jack up the rear of the
vehicle, and support securely on axle stands
(see “Jacking and Vehicle Support”)
positioned under the body side members.
Remove the roadwheel(s).
3Note the routing of the handbrake cable(s),
as an aid to refitting.
4Remove the relevant brake drum(s), with
reference to Section 11.
Longer cable
Removal
5Note the length of exposed thread at the
handbrake cable adjuster on the torsion
beam, then unscrew the adjuster nut from the
threaded rod.
6Disconnect the cable from the handbrake
lever operating rod on the vehicle underbody
(see illustration).
7Detach the cable from the guides on the
underbody. Note that the cable can be fed
through certain guides, but in some cases, the
guide brackets must be bent away from the
underbody to allow the cable to be withdrawn.
8Detach the cable from the adjuster on the
torsion beam.
9Unhook the cable end from the lever on the
brake shoe, then using a screwdriver, prise
out the lockplate that secures the handbrake
cable in the backplate.
10Withdraw the cable from the vehicle,
releasing it from the guide on the torsion
beam.
Refitting
11Refitting is a reversal of removal,
remembering the following points.
12Screw the adjuster nut onto the threaded
rod to the position noted before removal.
13Ensure that the handbrake cable is routed
as noted before removal.
14Refit the brake drum, (Section 11).
15Before refitting the roadwheel(s) and
lowering the vehicle to the ground, adjust the
handbrake, as described in Section 26.
Shorter cable
Removal
16Note the length of exposed thread at the
handbrake cable adjuster on the torsion
beam, then unscrew the adjuster nut from the
threaded rod. Continue as described in
paragraphs 8 to 10.
Braking system 9•19
27.6 Handbrake cable connection to handbrake lever operating
rod
1 Handbrake cable
2 Connecting link3 Handbrake lever operating rod26.14 Using a screwdriver to turn the handbrake adjuster wheel -
model with rear disc brakes
9