ECU FORD SIERRA 1988 2.G Braking System Workshop Manual

the caliper, free it using a screwdriver with the
guide pin bolt fitted, as shown (see
illustration). Do not use a screwdriver to free
the inboard pad, as this may damage the
piston dust seal. The inboard pad can be
freed by hand after lowering the caliper.
8Brush all dust and dirt from the caliper,
pads and disc, but do not inhale it as it may
be injurious to health. Scrape any corrosion
from the disc.
9As the new pads will be thicker than the old
ones, the piston must be pushed squarely into
its bore to accommodate the new thicker
pads. Depressing the piston will cause the
fluid level in the reservoir to rise so to avoid
spillage, syphon out some fluid using an old
hydrometer or a teat pipette. Do not lever
between the piston and disc to depress the
piston ideally a spreader tool, applying equal
force to both sides of the caliper, should be
used (see illustration).
10Further refitting is a reversal of removal
bearing in mind the following points.
11If disc pads with wear sensors are fitted,
the pad with the sensor wire should be fitted
inboard.
12Ensure that the anti-rattle clips are
correctly located on the caliper.
13Repeat the procedure on the opposite
front brake.
14On completion, apply the footbrake hard
several times to settle the pads, then check
and if necessary top-up the fluid level in the
reservoir. 15Avoid heavy braking, if possible, for the
first hundred miles or so after fitting new
pads. This will allow the pads to bed in and
reach full efficiency.
Teves caliper (Later 1.6, 1.8 and 2.0
litre models)
16Prise the retaining clip from the caliper.
Hold it with a pair of pliers to avoid it causing
personal injury.
17Unclip the pad wear sensor from the
caliper, and disconnect the wiring plug (see
illustration).
18Using a 7 mm Allen key, unscrew and
remove the two guide bolts securing the
caliper to the carrier bracket, and withdraw
the caliper (see illustration). Support the
caliper on an axle stand to avoid straining the
hydraulic hose.19Withdraw the disc pads from the caliper
(see illustration). It may be necessary to prise
the outboard pad with a screwdriver to
release it from the caliper. Do not use a
screwdriver to free the inboard pad, as this
may damage the piston dust seal.
20Proceed as described in paragraphs 8 to
15 inclusive, but in addition ensure that the
clip on the back of the inboard pad fits into
the piston recess (see illustration), refit the
caliper retaining clip, and ignore the reference
to the anti-rattle clips (see illustration). On
P100 models align the previously made marks
on the roadwheels and wheel studs.
Late model modification
21On some later models, slightly revised
front brake components are used. A new type
of retaining clip is used to secure the pads in
10•4Braking system
4.7 Correct and incorrect methods of freeing stuck outboard disc pad. Guide pin bolt (A)
must be in position - Girling caliper
4.9 Using a spreader tool to depress the
caliper piston into its bore
4.19 Withdraw the disc pads from the
caliper - Teves caliper4.18 Withdrawing a caliper from its carrier
bracket - Teves caliper
4.17 Disconnect the pad wear sensor
wiring plug - Teves caliper

11Remove the strut from the trailing shoe by
unhooking it from its spring. If a handbrake
lever is not attached to the new shoe, remove
the old lever by prising off the clip and driving
out the pin. Use a new clip on reassembly
(see illustration).
12Similarly transfer the self-adjuster
components to the new leading shoe. Note
that a small clearance (0.2 mm/0.008 in) must
exist between the underside of the smaller
ratchet segment and the brake shoe web.
Insert feeler blades of the correct thickness
beneath the ratchet when fitting the spring
clip, then withdraw the blades (see
illustration). The larger segment should be
fitted without any clearance.
13Commence reassembly by engaging the
self-adjuster ratchet teeth as shown (see
illustration).
14Offer the trailing shoe to the backplate,
fitting the handbrake cable to the handbrake
lever and (if not already done) the strut and
spring to the top of the shoe (see
illustration).
15Fit the leading shoe and adjuster
mechanism, engaging the hole in the adjuster
with the hook on the strut (see illustration).
16Fit the top and bottom return springs: this
is most easily done by allowing the ends of
the shoe to pass in front of the wheel cylinder
and the bottom pivot point, then engaging the
shoes in their correct positions after the
springs have been fitted. Be careful not to
damage the wheel cylinder rubber boots.17Fit and secure the hold-down pins,
springs and cups.
18Back off the self-adjuster mechanism, by
depressing the lower (small) ratchet segment,
to enable the brake drum to pass over the
shoes. Centre the shoes relative to the
backplate.
19Refit the drum, making sure that the small
hole is in line with one of the two large holes in
the drive flange. Secure the drum by pushing
the spire washer(s) over the wheel stud(s).
20Have an assistant operate the footbrake
several times: a series of clicks should be
heard from the drum as the self-adjuster
mechanism operates. When the clicking no
longer occurs, adjustment is complete.
21Renew the brake shoes on the other side
of the vehicle, then check the handbrake
adjustment.22Refit the roadwheels, lower the car and
tighten the wheel nuts.
23Avoid harsh braking if possible for the first
hundred miles or so until the new linings have
bedded in.
1.8 and 2.0 litre models
24Proceed as described in paragraph 5, but
on P100 models mark the position of the
brake drum in relation to one of the wheel
studs (see illustration).
25Remove the hold-down cup, spring and
pin from the leading (front) shoe by
depressing the cup and turning it through 90º
(see illustration).
26Note the fitted positions of the shoe return
springs for reference when refitting, then
release the leading shoes from the wheel
cylinder and the anchor bracket using a
screwdriver as a lever.
Braking system 10•7
10
5.10 Lubrication points on brake backplate
5.15 Engage the hole in the adjuster with
the hook on the strut (arrowed)5.14 Strut and spring fitted to top of trailing
shoe
5.13 Fully retract the self-adjuster ratchet
(arrowed) before refitting the trailing shoe5.12 Using feeler blades to set clearance
between smaller ratchet segment and
brake shoe web. Spring clip arrowed5.11 Handbrake lever-to-trailing shoe
securing clip (arrowed)
5.9 Disconnecting the handbrake cable
from the trailing shoe lever5.7 Using pliers to remove a shoe hold-
down cup

27Unhook the return springs and remove the
leading shoe. Note the direction of wheel
rotation arrows on the shoes.
28Remove the hold-down cup, spring and
pin from the trailing (rear) shoe by depressing
the cup and turning it through 90º.
29Withdraw the trailing shoe and disconnect the
handbrake cable from the lever (see illustration).30Unhook the springs from the trailing shoe
and remove the self-adjuster strut.
31Clean and inspect all components and
lubricate the shoe contact points on the
backplate - refer to illustration, paragraph 10.
Take care not to inhale any dust, as it may be
injurious to health.32Commence reassembly by fitting the
springs to the trailing shoe and attaching the
self-adjuster strut.
33Attach the handbrake cable to the lever
and position the trailing shoe on the wheel
cylinder and anchor bracket. Ensure that the
upper return spring is located on the
self-adjuster strut.
34Refit the hold-down pin, spring and cup to
the trailing shoe.
35Connect the return springs to the leading
shoe, then locate the lower end in the anchor
bracket and lever the upper end onto the
toothed quadrant lever and wheel cylinder. Be
careful not to damage the wheel cylinder
rubber boot.
36Refit the hold-down pin, spring and cup to
the leading shoe.
37Using a screwdriver, push the
self-adjuster toothed quadrant fully towards
the backplate to its initial setting.
38Proceed as described in paragraphs 19 to
23 inclusive, but on P100 models, align the
previously made marks on the brake drums
and wheel studs, and on the roadwheels and
brake drums.
Removal
1Apply the handbrake, loosen the relevant
roadwheel nuts, then jack up the front of the
vehicle and support on axle stands. (see
“Jacking and Vehicle Support”). Remove the
roadwheel. On P100 models, mark the
position of the roadwheel in relation to one of
the wheel studs before removal.
2Remove the brake fluid reservoir cap and
secure a piece of polythene over the filler
6Front disc caliper - removal,
overhaul and refitting
10•8Braking system
5.24 Exploded view of rear drum brake assembly - 1.8 and 2.0 litre models
A Leading brake shoe
B Dust-excluding seal
C Piston
D Piston seal
E SpringF Wheel cylinder housing
G Bolts
H Hold-down pin
J Brake backplate
K Adjuster plungerL Trailing brake shoe
M Self-adjuster strut
N Hold-down spring and
cup
5.25 Leading shoe hold-down cup (arrowed)5.29 Removing the trailing brake shoe
A Handbrake cable and slot
Caution: Refer to the
precautions in Section 1.

Note: Complete dismantling of the rear caliper
should not be attempted unless Ford spring
compressor (tool No 12-007) is available, or
unless the problems likely to arise in the
absence of the tool are understood. Renewal
of the piston seal dust-excluding seal and
piston adjuster nut seal requires no special
tools.
Removal
1With the ignition switched off, pump the
brake pedal at least 20 times, or until it
becomes hard, to depressurise the system.
2Chock the front wheels, slacken the
relevant roadwheel nuts, then jack up the rear
of the vehicle and support on axle stands (see
“Jacking and Vehicle Support”). Remove the
roadwheel and release the handbrake.
3Where applicable, disconnect the wiring to
the disc pad wear sensor.
4Proceed as described in Section 6,
paragraphs 2 and 3, but note that the rigid
brake pipe is clipped to the suspension lower
arm.
5Unscrew and remove the two guide bolts
securing the caliper to the carrier bracket,
while holding the pins with a spanner. Unhookthe handbrake cable from the lever, and
withdraw the caliper. Alternatively, the two
carrier bracket-to-hub carrier bolts can be
unscrewed, and the caliper and carrier can be
separated on the bench, but in this case the
handbrake cable must be disconnected from
the carrier bracket by removing the retaining
circlip.
Overhaul
6Clean the caliper, taking care not to inhale
any dust which may be injurious to health, and
mount it in a soft-jawed vice.
7Rotate the piston anti-clockwise, using
Ford tool No 12-006, or a pair of circlip pliers
or similar tool, until it protrudes from the
caliper bore by approximately 20.0 mm (0.8
in). Free the dust-excluding seal from the
groove in the piston, then continue
unscrewing the piston and remove it. Remove
and discard the dust-excluding seal.
8The piston and bore may now be cleaned
and examined as described in Section 6,
paragraph 12.
9The piston adjuster nut seal should be
renewed as follows.
10Remove the circlip from the piston, then
extract the thrustwashers, wave washer and
thrust bearing. Note the fitted sequence of
these components. Finally remove the nut
(see illustrations).
11Remove the seal from the nut, noting
which way round it is fitted. Clean the nut with
methylated spirit. Lubricate the new seal with
clean hydraulic fluid and fit it to the nut.12If no further dismantling is required,
proceed to paragraph 20.
13For further dismantling it is virtually
essential to have Ford tool 12-007 in order to
compress the adjuster spring. This tool
appears to be a cut-down adjuster nut with a
handle for turning it. In the workshop it was
found that the actual piston adjuster nut could
be used to compress the spring if it were
turned with circlip pliers (see illustration).
This works well enough for dismantling, but
reassembly proved extremely difficult
because of the limited clearance between the
skirt of the nut and the caliper bore.
14Having compressed the adjuster spring
just enough to take the load off the circlip,
release the circlip inside the caliper bore.
Remove the spring compressor, then extract
the circlip, spring cover, spring and washer
(see illustrations).
7Rear disc caliper - removal,
overhaul and refitting
10•10Braking system
7.10a Remove the circlip from the rear
caliper piston . . .7.10c . . . a wave washer and (not shown)
another thrustwasher . . .
7.14a Extract the circlip from the caliper
bore . . .
7.13 Using the piston adjuster nut to
compress the adjuster spring7.10e . . . and finally the adjuster nut itself.
Note the seal (arrowed) on the nut7.10d . . . then the thrust bearing . . .
7.10b . . . followed by the thrustwasher . . .
Caution: Refer to the
precautions in Section 1.

15A long thin pair of circlip pliers will now be
required to release the key plate retaining
circlip from the caliper bore (see illustration).
With the circlip removed, the pushrod and key
plate can be pulled out.
16Remove the handbrake strut from the
caliper bore.
17Remove the handbrake lever return spring
and stop bolt. Pull the lever and shaft nut out
of the caliper. Prise out the shaft seal (see
illustration).
18Clean the handbrake shaft using wire
wool; renew the shaft if it is badly corroded.
The shaft bush in the caliper can also be
renewed if necessary. Pull out the old bush
with an internal puller or slide hammer, and
press in the new bush to 7.5 mm (0.30 in)
below the shaft seal lip (see illustration). The
slot in the side of the bush must line up with
the pushrod bore in the caliper.19Having renewed components as
necessary, commence reassembly by
smearing a little brake grease or anti-seize
compound on the handbrake shaft and bush.
20Fit a new handbrake shaft seal to the
caliper. Pass the shaft through the seal and
into the caliper, taking care not to damage the
seal lips.
21Refit the handbrake lever stop bolt and
return spring.
22Refit the handbrake strut, lubricating it
with brake grease.
23Fit a new O-ring to the base of the
pushrod. Refit the pushrod and the key plate,
engaging the pip on the key plate with the
recess in the caliper. Secure the key plate
with the circlip.
24Refit the washer, spring and spring cover.
Compress the spring and refit the circlip, then
release the spring compressor.
25Lubricate the caliper bore with clean
hydraulic fluid and fit a new piston seal.
26Reassemble the piston components.
Lubricate the contact face of the adjuster nut
with a little brake grease, then fit the adjuster
nut (with new seal), thrust bearing,
thrustwasher, wave washer and the second
thrustwasher. Secure with the circlip.
27Fit a new dust-excluding seal to the
grooves in the piston and caliper bore as the
piston is refitted (see illustration). Screw the
piston into the caliper bore with the tool used
during removal.
28Renew the guide pin gaiters and apply a
little brake grease or anti-seize compound to
the guide pins when refitting the caliper to its
carrier bracket.
Refitting
29Refitting is a reversal of removal, but on
completion bleed the rear brake circuit and
check the operation of the handbrake.
Note: From 1987, thicker brake discs were
fitted. If the later discs are fitted to earlier
models, longer wheel studs must be fitted to
accommodate the increased thickness.
Consult a dealer for further advice.
Front disc
1Apply the handbrake, loosen the relevant
roadwheel nuts, then jack up the front of the
vehicle and support on axle stands (see
“Jacking and Vehicle Support”). Remove the
roadwheel.
2Remove the disc caliper and carrier bracket
but do not disconnect the flexible hose.
Support the caliper on an axle stand to avoid
straining the flexible hose.
3Rotate the 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 reground by a suitable
specialist. Scrape any corrosion from the disc.
4Using a dial gauge or a flat metal block and
feeler blades, check that the disc run-out
does not exceed the limit given in the
8Brake disc - examination,
removal and refitting
Braking system 10•11
10
7.14d . . . and the washer
7.27 Dust-excluding seal fitted to piston
and caliper bore7.18 Handbrake shaft bush correctly fitted
X = 7.5 mm (0.30 in)7.17 Handbrake shaft and associated
components
7.15 Remove the circlip (ends arrowed) to
release the pushrod and key plate
7.14c . . . the spring itself . . .7.14b . . . then the spring cover . . .
Caution: Refer to the
precautions in Section 1.

Specifications. To do this, fix the measuring
equipment, and rotate the disc, noting the
variation in measurement as the disc is
rotated. The difference between the minimum
and maximum measurements recorded is
known as disc run-out.
5Mark the position of the brake disc in
relation to the drive flange and on Saloon,
Hatchback and Estate models, remove the
retaining screw or spire washer(s), as
applicable, and remove the disc. On P100
models, also mark the position of the wheel
adapter plate in relation to the disc and drive
flange, then unscrew the five retaining nuts
and remove the wheel adapter plate and disc.
6Refitting is a reversal of removal, but when
refitting ensure that the mating faces of the
disc, drive flange and on P100 models the
wheel adapter plate, are clean. Align the
marks made on the disc, drive flange, and
where applicable the wheel adapter plate,
during removal. Refit the disc caliper and
carrier bracket.
Rear disc
7Chock the front wheels, loosen the relevant
roadwheel nuts, then jack up the rear of the
vehicle and support on axle stands.(see
“Jacking and Vehicle Support”).Remove the
roadwheel and release the handbrake.
8Detach the handbrake cable from the
retaining clip on the lower arm.
9Unscrew the two caliper carrier
bracket-to-hub carrier bolts and remove the
caliper assembly. Support the caliper on an
axle stand to avoid straining the flexible hose.
10Proceed as described in paragraphs 3
and 4.
11Mark the position of the brake disc in
relation to the drive flange, remove the
retaining spire washer(s), and withdraw the
disc.
12Refitting is a reversal of removal, but
ensure that the mating faces of the disc and
drive flanges are clean, and align the marks
made on the disc and drive flange during
removal.
1Whenever a brake drum is removed, brush
out the dust, taking care not to inhale any, as
it may be injurious to health.
2Examine the internal friction surface of the
drum. If deeply scored, or so worn that the
drum has become ridged to the width of the
shoes, then both drums must be renewed.
3Regrinding is not recommended as the
internal diameter of the drum will no longer be
compatible with the shoe friction material
contact diameter.
Saloon, Hatchback and Estate
models
1Chock the front wheels, loosen the relevant
roadwheel nuts, then jack up the rear of the
vehicle and support on axle stands (see
“Jacking and Vehicle Support”).Remove the
roadwheel and release the handbrake.
2Remove the retaining spire washer(s) from
the wheel stud(s) and pull off the brake drum.
If the drum will not pass over the shoes, it is
possible to release the automatic adjuster
mechanism by inserting a screwdriver through
the small hole in the drum and pressing down
on the ratchet.
3Remove 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 union nut and disconnect the
fluid pipe from the wheel cylinder (see
illustration). Plug the open ends of the pipe
and wheel cylinder to prevent fluid loss and
dirt ingress.
5Pull the tops of the brake shoes apart so
that the self-adjuster mechanism holds them
clear of the wheel cylinder.
6Unscrew the two retaining bolts from the
rear of the brake backplate, and withdraw the
wheel cylinder and sealing ring.
7The wheel cylinder can now be dismantled
as follows.
8Prise the dust-excluding rubber seals from
the ends of the wheel cylinder, and withdraw
the pistons and central spring, identifying the
pistons so that they can be refitted in their
original positions.
9Prise the seals from the pistons.
10Clean all the components in methylated
spirit and allow to dry. Examine the surfaces
of the pistons and cylinder bore for wear,
scoring and corrosion. If evident, the
complete wheel cylinder must be renewed,
but if the components are in good condition,
discard the seals and obtain a repair kit.
11Dip the new seals in clean brake fluid and
fit them to the piston grooves, using fingers
only to manipulate them. Ensure that the seal
lips face into the wheel cylinder.
12Carefully insert the pistons and central
spring into the cylinder, and fit the
dust-excluding rubber seals. Ensure that the
pistons are fitted in their original positions.
13Wipe the brake backplate clean, then fit
the wheel cylinder together with a new sealing
ring, and tighten the securing bolts.14Reconnect the fluid pipe to the wheel
cylinder and tighten the union nut.
15Using a screwdriver, push the
self-adjuster toothed quadrant fully towards
the backplate to its initial setting.
16Further refitting is a reversal of removal,
but on completion apply the footbrake several
times in order to set the brake shoes in their
normal positions, and bleed the rear brake
circuit.
P100 models
17The procedure is as described in
paragraphs 1 to 16 inclusive, but with the
following differences.
18Before removing the roadwheel, mark its
position in relation to the brake drum.
Similarly, mark the position of the brake drum
in relation to one of the wheel studs. Align the
marks when refitting.
19The wheel cylinder is secured to the brake
backplate by a circlip instead of the two bolts
used on other models (see illustration).
Saloon, Hatchback and Estate
models
1Remove the rear brake shoes.
2Disconnect the handbrake cable from the
backplate by extracting the U-clip.
11Rear brake backplate (drum
brakes) - removal and refitting
10Rear wheel cylinder (drum
brakes) -removal,overhaul
andrefitting
9Brake drum -inspectionand
renewal
10•12Braking system
10.4 Fluid pipe union (1) and wheel cylinder
retaining bolts (2)
10.19 Wheel cylinder securing circlip
(arrowed)
Caution: Refer to the
precautions in Section 1.
Caution: Refer to the
precautions in Section 1.

3Remove the wheel cylinder.
4Remove the driveshaft but do not refit the
securing bolts to the backplate.
5Remove the backplate.
6If required, prise out the handbrake stop
button.
7Refitting is a reversal of removal.
P 100 models
Note: When refitting the backplate, a new rear
hub nut and driveshaft O-ring must be used.
8Proceed as described in paragraphs 1 to 3
inclusive.
9Remove the driveshaft.
10Relieve the staking on the rear hub nut,
and using a 50 mm socket and a suitable
extension bar, unscrew the nut. Note that the
nut is extremely tight.
11Pull off the hub.
12Unscrew the six retaining nuts and
remove the backplate and the oil baffle (see
illustration).
13If required, prise out the handbrake stop
button.
14Refitting is a reversal of removal, bearing
in mind the following points.
15When refitting the backplate and the oil
baffle, coat the area of the oil baffle shown
(see illustration - Chapter 9) with sealant to
Ford spec SPM-4G-9112-F, then refit the
baffle and the backplate to the axle, tightening
the six securing nuts to the specified torque.
16Use a new rear hub nut, and tighten to the
specified torque. Stake the nut into the groove
in the axle tube after tightening.
17Refit the driveshaft, using a new O-ring.
Note: A suitable puller will be required to
remove the drive flange, and a new rear hub
nut must be used on reassembly.
Removal
1Loosen the rear hub nut with the vehicle
resting on its wheels. Note that the left-hand
nut has a left-hand thread, ie it is undone in a
clockwise direction. Before loosening the nut,
ensure that the handbrake is applied, and
chock the relevant rear wheel. A suitable
extension bar will be required, as the nut is
extremely tight.
2Loosen the relevant rear roadwheel nuts,
chock the front wheels, then jack up the rear
of the vehicle and support on axle stands (see
“Jacking and Vehicle Support”).Remove the
roadwheel and release the handbrake.
3Free the handbrake cable from its clip on
the suspension lower arm.
4Unscrew the two caliper carrier
bracket-to-hub carrier bolts, and remove the
caliper, supporting it on an axle stand to avoid
straining the flexible hose.
5Mark the position of the brake disc in
relation to the drive flange, remove the
retaining spire washer(s), and remove the
disc.
6Unscrew and remove the rear hub nut, and
using a suitable puller, pull off the drive flange.
7Unscrew the four bolts securing the hub
carrier and splash shield to the lower arm.
Remove the hub carrier and splash shield,
whilst supporting the driveshaft. Support the
driveshaft by placing axle stands underneath
it, or by securing with string to the underbody.
Avoid bending the driveshaft joints to
excessive angles, and do not allow the shaft
to hang down from one end.
Refitting
8Refitting is a reversal of removal, bearing in
mind the following points.
9When reassembling the drive flange and the
hub carrier, fit the drive flange to the hub
carrier in order to centralise the bearings, then
using a soft-faced mallet, drive the drive
flange/hub carrier assembly onto the end of
the stub axle.10Refit the hub carrier/splash
shield-to-lower arm securing bolts. Note that
there are two types of bolts used to secure
the rear hub carrier to the lower arm. The two
types of bolt must not be mixed on a vehicle
but can be changed in complete sets for the
alternative type. A complete set is eight bolts,
four each side. Note that the two types of bolt
have different torque wrench settings. When
renewing the wheel bearings a suitable puller
will be required to remove the drive flange,
and a new rear hub nut must be used on
reassembly.
11When refitting the brake disc, align the
previously made marks on disc and drive
flange.
12Fit a new rear hub nut of the correct type,
and tighten it with the vehicle resting on its
roadwheels. Apply the handbrake and chock
the relevant rear wheel when finally tightening
the hub nut.
Note: Before commencing overhaul obtain a
repair kit containing new pistons and seals.
Removal
1Depress the brake pedal several times to
dissipate the vacuum in the servo.
2Disconnect the wiring plug from the low
fluid level switch on the fluid reservoir cap
(see illustration).
3Place a suitable container beneath the
master cylinder, then unscrew the union nuts
and disconnect the two fluid pipes. Plug the
ends of the pipes to prevent dirt ingress.
13Master cylinder (conventional
braking system) - removal,
overhaul and refitting
12Rear disc splash shield -
removal and refitting
Braking system 10•13
10
13.2 Disconnect the wiring plug from the low fluid level switch
(arrowed)11.12 Brake backplate and oil baffle retaining nuts
Caution: Refer to the
precautions in Section 1.
Caution: Refer to the
precautions in Section 1.

4Unscrew the two mounting nuts and spring
washers, and withdraw the master cylinder
from the servo. Cover the master cylinder with
rag or a plastic bag to prevent spillage of
hydraulic fluid on the vehicle paintwork. If fluid
is accidentally spilt on the paintwork, wash off
immediately with cold water.
Overhaul
5Drain the remaining fluid from the master
cylinder, and clean the exterior surfaces with
methylated spirit.
6Pull the fluid reservoir from the top of the
master cylinder and prise out the sealing
rubbers (see illustration).
7Mount the master cylinder in a vice, then
depress the primary piston slightly and extract
the circlip and washer. Withdraw the primary
piston assembly.
8Depress the secondary piston and remove
the stop pin from the fluid aperture.
9Remove the master cylinder from the vice
and tap it on the bench to remove the
secondary piston assembly.
10Prise the seals from the secondary piston.
Do not attempt to dismantle the primary
piston.
11Clean all the components in methylated
spirit and examine them for wear and
damage. In particular check the surfaces of
the pistons and cylinder bore for scoring and
corrosion. If the cylinder bore is worn, renew
the complete master cylinder, otherwise
obtain a repair kit including pistons and seals.
12Check that the fluid inlet and outlet ports
are free and unobstructed. Dip the new
pistons and seals in clean brake fluid.
13Fit the seals to the secondary piston using
the fingers only to manipulate them into the
grooves. Note that the sealing lips must face
away from each other.
14Insert the secondary piston and spring
into the cylinder. Turn the piston slowly as the
first seal enters to avoid trapping the sealing
lip. Similarly insert the primary piston and
spring, then fit the washer and circlip.
15Depress the primary and secondary
pistons and refit the secondary piston stop
pin.
16Fit the fluid reservoir sealing rubbers andpress the reservoir into them. If the rubbers
are worn or perished, or if leakage has been
evident, fit the new rubbers.
Refitting
17Refitting is a reversal of removal but
tighten the mounting nuts and pipe union nuts
to the specified torque and finally bleed the
hydraulic system.
Removal
1To remove the servo, first remove the
master cylinder.
2Disconnect the vacuum hose from the
servo (see illustration).
3Working inside the vehicle, remove the
lower facia panel from the driver’s side.
4Remove the clip from the servo pushrod on
the brake pedal (see illustration).
5Unscrew the two mounting nuts and
washers securing the servo to the bulkhead,
and lift the servo from the bulkhead. Note that
the two mounting nuts also secure the pedal
bracket to the bulkhead.6If required, the vacuum hose can be
disconnected from the inlet manifold, and the
non-return valve can be checked for correct
operation by ensuring that it is only possible
to blow through it in one direction.
7No overhaul of the servo is possible, and if
faulty, it must be renewed as a complete unit.
Refitting
8Refitting is a reversal of removal, but when
refitting the servo to the bulkhead, ensure that
the pushrod is correctly located in the pedal
and that the clip is secure.
Vacuum hose - modification
9From mid-1989, a new type of brake servo
vacuum hose-to-inlet manifold connector has
been used in production. The connector
comprises three parts; a collet which locks
the hose in position, an O-ring, and a brass
insert which is pressed into the inlet manifold.
10To disconnect the hose from the inlet
manifold, apply light even pressure, push and
hold the flange of the collet against the
manifold. While holding the collet forward,
gently pull the hose from the collet (see
illustration). Take care not to pull at an angle
or use excessive force, as this can cause the
collet to snatch and lock the hose.
11To reconnect the hose, push the hose into
the collet until the swage on the hose is hard
against the collet flange. Pull gently on the
hose to check that it is locked by the collet.
14Vacuum servo (conventional
braking system) - removal and
refitting
10•14Braking system
14.10 Disconnecting a later-type brake
servo vacuum hose14.4 Remove the clip (arrowed) from the
servo pushrod14.2 Servo vacuum hose non-return valve
(A) and servo connection (B) - conventional
braking system
13.6 Exploded view of master cylinder -
conventional braking system
A Fluid reservoir
B Sealing rubber
C Spring
D Secondary piston
E Primary piston
F Stop pin
Caution: Refer to the
precautions in Section 1.

Note: New seals must be used between the
reservoir and the hydraulic unit on reassembly.
Removal
1Disconnect the battery negative lead.
2Depressurise the hydraulic system by
pumping the brake pedal at least 20 times, or
until it becomes hard.
3Disconnect the wiring multi-plugs from the
reservoir cap and remove the cap.
4Unscrew the reservoir securing screw, and
remove the securing clip, noting that the clip
also supports the clutch cable (see illustration).5Prepare a suitable container to collect the
fluid as the hydraulic unit is drained, then
remove the securing spring clip and
disconnect the low pressure fluid hose from
the pump (see illustrations). Allow the fluid to
drain out of the hose into the container. If fluid
is accidentally spilt on the paintwork, wash off
immediately with cold water.
6Pull the reservoir out of the seals on the
hydraulic unit and remove it (see illustration).
7Note the spigot locating bush on the rear
hydraulic unit inlet, which may stay in the
hydraulic unit or may come out with the
reservoir (see illustration).
Refitting
8Refitting is a reversal of removal, but use
new seals between the reservoir and the
hydraulic unit.
9On completion, bleed the complete
hydraulic system and check for leaks around
all disturbed components.Note: A new gasket must be used between
the hydraulic unit and the bulkhead on
refitting.
Removal
1Disconnect the battery negative lead.
2Depressurise the hydraulic system by
pumping the brake pedal at least 20 times, or
until it becomes hard.
3Disconnect the six multi-plugs from the
hydraulic unit. They are all different, so there
is no need to label them. When a plug has a
spring clip retainer, lift the clip before pulling
out the plug. To release the pump plug, pull
back the rubber boot and the plug sleeve (see
illustrations).
4Unbolt the earth strap from the unit.
5Prepare a suitable container to catch spilt
fluid. Mark the hydraulic pipes so that they
can be refitted in their original positions, then
disconnect them from the base of the unit.
Plug the open ends of the pipes and hydraulic
unit to prevent fluid leakage and dirt ingress. If
fluid is accidentally spilt on the paintwork,
wash off immediately with cold water.
6Working inside the vehicle, remove the
lower facia panel from the driver’s side.
16Hydraulic unit (ABS)
- removal and refitting
15Fluid reservoir (ABS)
- removal and refitting
Braking system 10•15
10
15.5b . . . and disconnect the low pressure
fluid hose - ABS
16.3c . . . and the pressure switch
multi-plug - ABS16.3b . . . the main valve multi-plug . . .16.3a Disconnecting the low fluid level
switch multi-plug . . .
15.7 Removing the spigot locating bush
from the rear hydraulic unit inlet - ABS15.6 Removing the fluid reservoir from the
hydraulic unit - ABS
15.5a Remove the securing spring clip . . .15.4 Reservoir securing clip (arrowed) also
supports clutch cable - ABS
Caution: Refer to the
precautions in Section 1.
Caution: Refer to the
precautions in Section 1.

7Remove the clip from the hydraulic unit
pushrod on the brake pedal.
8With an assistant supporting the hydraulic
unit, unscrew the four nuts which secure the
unit to the bulkhead (see illustration).
Withdraw the unit from under the bonnet.
9Recover the gasket fitted between the unit
and the bulkhead.
10Drain the fluid from the reservoir. Do not
actuate the pushrod with the unit removed.
11Dismantling of the hydraulic unit should
be limited to the operations described in the
following Sections (see illustration).
Refitting
12Refitting is a reversal of removal, bearing
in mind the following points.13Do not refill the fluid reservoir until
reassembly and refitting is complete.
14Use a new gasket between the hydraulic
unit and the bulkhead.
15Ensure that the hydraulic pipes are
reconnected to the correct unions.
16On completion, bleed the complete
hydraulic system and check for leaks around
all disturbed components.
Note: A new O-ring must be used between
the accumulator and the hydraulic unit on
refitting.
Removal
1Disconnect the battery negative lead.
2Depressurise the hydraulic system by
pumping the brake pedal at least 20 times, or
until it becomes hard.
3Wrap a clean rag round the base of the
accumulator to catch any spilt fluid.
4Unscrew the accumulator using a hexagon
key. Remove the accumulator, noting the
sealing ring and being prepared for fluid
spillage (see illustration). If fluid isaccidentally spilt on the paintwork, wash off
immediately with cold water.
Refitting
5Fit a new O-ring to the base of the
accumulator, fit the accumulator and tighten
it.
6Reconnect the battery. Switch on the
ignition and check that the hydraulic unit
pump stops within 60 seconds; if not, the
accumulator is likely to be faulty.
7On completion, bleed the complete
hydraulic system and check for leaks around
all disturbed components.
Note: New sealing washers must be used on
the high pressure fluid hose banjo union, and
a new O-ring must be used between the
accumulator and the hydraulic unit on refitting.
Removal
1Remove the accumulator.
2Prepare a suitable container to catch spilt
fluid, and disconnect the high pressure fluid
hose from the pump.
3Remove the securing spring clip and
disconnect the low pressure fluid hose from
the pump. Allow the fluid to drain out of the
hose into the container. If fluid is accidentally
spilt on the paintwork, wash off immediately
with cold water.
4Disconnect the multi-plugs from the
pressure switch and the pump motor.
5Remove the pump mounting bolt (see
illustration).
6Pull the pump and motor assembly off the
mounting spigot and remove it.
7Recover the mounting bushes and renew
them if necessary.
8If a new pump is to be fitted, transfer the
pressure switch to it, using a new O-ring.
18Hydraulic unit pump and motor
(ABS) - removal and refitting
17Hydraulic unit accumulator
(ABS) - removal and refitting
10•16Braking system
16.8 Hydraulic unit-to-bulkhead securing
nuts (arrowed) - ABS
17.4 Unscrew the accumulator and remove
it, noting the O-ring (arrowed)
16.11 Hydraulic unit components - ABS
A Fluid reservoir
B Accumulator
C Main valveD Master cylinder
E Pushrod
F Pump and motorG Booster
H Pressure switch
J Valve block
Caution: Refer to the
precautions in Section 1.
Caution: Refer to the
precautions in Section 1.