lock FORD SIERRA 1989 2.G Braking System Workshop Manual
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Page 1 of 22
System type
Conventional braking system (except P100 models) . . . . . . . . . . . . . . . Front discs and rear drums with vacuum servo assistance, dual
hydraulic circuit split front/rear, deceleration sensitive pressure relief
valve in rear hydraulic circuit. Cable-operated handbrake on rear
wheels.
ABS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Front and rear discs operated via electrically-driven hydraulic pump,
dual hydraulic circuit split front/rear, pressure regulating valve in rear
hydraulic circuit. Cable-operated handbrake on rear wheels
P100 models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Front discs and rear drums with vacuum servo assistance, dual
hydraulic circuit split front/rear, load apportioning valve in rear
hydraulic circuit. Cable-operated handbrake on rear wheels
Front discs
Type:
1.3 and 1.6 litre models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Solid
1.8 and 2.0 litre models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ventilated
Diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240.0 mm (9.46 in)
Maximum disc run-out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.15 mm (0.006 in)
Minimum pad friction material thickness . . . . . . . . . . . . . . . . . . . . . . . . 1.5 mm (0.06 in)
Rear discs
Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Solid
Diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252.7 mm (9.96 in)
Maximum disc run-out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.15 mm (0.006 in)
Minimum pad friction material thickness . . . . . . . . . . . . . . . . . . . . . . . . 1.5 mm (0.06 in)
Rear drums
Internal diameter:
1.3 and 1.6 litre Saloon and Hatchback models . . . . . . . . . . . . . . . . . 203.2 mm (8.0 in)
1.8 and 2.0 litre Saloon and Hatchback models and all Estate models .228.6 mm (9.0 in)
P100 models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256.0 mm (10.1 in)
Minimum shoe friction material thickness . . . . . . . . . . . . . . . . . . . . . . . 1.0 mm (0.04 in)
Chapter 10
Braking system
Brake disc - examination, removal and refitting . . . . . . . . . . . . . . . . . .8
Brake drum - inspection and renewal . . . . . . . . . . . . . . . . . . . . . . . . .9
Brake fluid pipes and hoses - removal and refitting . . . . . . . . . . . . . .26
Brake hydraulic system (ABS) - bleeding . . . . . . . . . . . . . . . . . . . . . . .3
Brake hydraulic system (conventional braking system) - bleeding . . .2
Brake pedal - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . .30
Computer module (ABS) - removal and refitting . . . . . . . . . . . . . . . .21
Deceleration sensitive valve (Saloon, Hatchback and Estate models
with conventional braking system) - removal and refitting . . . . . . .23
Disc pads - inspection and renewal . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Fluid reservoir (ABS) - removal and refitting . . . . . . . . . . . . . . . . . . . .15
Front disc caliper - removal, overhaul and refitting . . . . . . . . . . . . . . .6
General information and precautions . . . . . . . . . . . . . . . . . . . . . . . . . .1
Handbrake cable - adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
Handbrake cable - removal and refitting . . . . . . . . . . . . . . . . . . . . . .27
Handbrake lever - removal and refitting . . . . . . . . . . . . . . . . . . . . . . .29Hydraulic unit (ABS) - removal and refitting . . . . . . . . . . . . . . . . . . . .16
Hydraulic unit accumulator (ABS) - removal and refitting . . . . . . . . .17
Hydraulic unit pressure switch (ABS) - removal and refitting . . . . . . .19
Hydraulic unit pump and motor (ABS) - removal and refitting . . . . . .18
Load apportioning valve (P100 models) - adjustment . . . . . . . . . . . .25
Load apportioning valve (P100 models) - removal and refitting . . . . .24
Master cylinder (conventional braking system) - removal, overhaul and
refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Rear brake backplate (drum brakes) - removal and refitting . . . . . . .11
Rear drum brake shoes - inspection and renewal . . . . . . . . . . . . . . . .5
Rear disc caliper - removal overhaul and refitting . . . . . . . . . . . . . . . .7
Rear disc splash shield - removal and refitting . . . . . . . . . . . . . . . . .12
Rear wheel cylinder (drum brakes) - removal, overhaul and refitting .10
Vacuum servo (conventional braking system) - removal and refitting .14
Valve block (ABS) - removal and refitting . . . . . . . . . . . . . . . . . . . . . .20
Wheel sensor (ABS) - removal and refitting . . . . . . . . . . . . . . . . . . . .22
10•1
Specifications Contents
10
Easy,suitable for
novice with little
experienceFairly easy,suitable
for beginner with
some experienceFairly difficult,
suitable for competent
DIY mechanic
Difficult,suitable for
experienced DIY
mechanicVery difficult,
suitable for expert
DIY or professional
Degrees of difficulty
Page 2 of 22
Torque wrench settingsNmlbf ft
Caliper carrier bracket-to-hub carrier bolts . . . . . . . . . . . . . . . . . . . . . .51 to 6138 to 45
Front caliper guide bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 to 2515 to 18
Rear caliper guide bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31 to 3523 to 26
Rear brake backplate nuts - P100 models . . . . . . . . . . . . . . . . . . . . . . .45 to 5433 to 40
Servo-to-bulkhead nuts (conventional braking system) . . . . . . . . . . . . .35 to 4526 to 33
Master cylinder-to-servo nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 to 2515 to 18
Hydraulic unit-to-bulkhead nuts (ABS) . . . . . . . . . . . . . . . . . . . . . . . . . .41 to 5130 to 38
Hydraulic unit accumulator (ABS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34 to 4625 to 34
Pump mounting bolt (ABS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 to 95 to 7
High pressure hose-to-pump union (ABS) . . . . . . . . . . . . . . . . . . . . . . .7 to 125 to 9
Wheel sensor mounting bolts (ABS) . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 to 116 to 8
General information
The braking system is of the dual circuit
hydraulic type. The front and rear circuits are
operated independently from a tandem
master cylinder, so that in the event of a
hydraulic failure in one circuit, full braking
force will still be available to two wheels
through the remaining circuit.
A deceleration sensitive valve on Saloon,
Hatchback and Estate models not fitted with
an Anti-lock Braking System (ABS), and a load
apportioning valve on P100 models, is
incorporated in the rear brake hydraulic
circuit. The valve regulates the pressure
applied to the rear brakes and reduces the
possibility of the rear wheels locking under
heavy braking.
All models are fitted with front disc brakes,
with solid or ventilated discs depending on
model. The calipers are of single piston sliding
type, which ensures that equal pressure is
applied to each disc pad.
Non-ABS models are fitted with rear disc
brakes or rear drum brakes, incorporating
leading and trailing shoes operated by
double-acting wheel cylinders. A self-adjuster
mechanism is fitted which consists of a
toothed quadrant which is kept in contact with
a toothed pin attached to the shoe strut by
means of a spring. The quadrant incorporates
an arm which locates in a slot in the leading
shoe. As the shoe linings wear the quadrant is
pulled from the pin when the footbrake is
operated, and automatically repositioned to
effectively lengthen the shoe strut.
ABS is available as an option for all models
except the P100. The system comprises an
electronic control unit, roadwheel sensors,
hydraulic actuator with electrically-driven
hydraulic pump, and the necessary valves and
switches. Disc brakes are fitted to all four
wheels. The front disc brakes are similar to
those fitted to non-ABS models, but the rear
brakes incorporate a self-adjusting
mechanism, and a mechanical handbrake
mechanism. The purpose of the system is to
prevent wheel(s) locking during heavy brake
applications. This is achieved by automatic
release of the brake on the locked wheel,followed by reapplication of the brake. This
procedure is carried out four times per second
by the control valves in the valve block. The
valves are controlled by the electronic control
unit which itself receives signals from the
wheel sensors, which monitor the locked or
unlocked state of the wheels. A pressure
regulating valve is incorporated in the rear
hydraulic circuit to maintain the desired
pressure ratio between the front and rear
circuits.
Precautions
Note: Hydraulic fluid is poisonous; wash off
immediately and thoroughly in the case of skin
contact and seek immediate medical advice if
any fluid is swallowed or gets into the eyes.
Certain types of hydraulic fluid are
inflammable and may ignite when allowed into
contact with hot components; when servicing
any hydraulic system it is safest to assume
that the fluid is inflammable and to take
precautions against the risk of fire as though it
is petrol that is being handled. Hydraulic fluid
is also an effective paint stripper and will
attack plastics; if any is spilt, it should be
washed off immediately using copious
quantities of fresh water. Finally, it is
hygroscopic (it absorbs moisture from the air)
old fluid may be contaminated and unfit for
further use. When topping-up or renewing the
fluid, always use the recommended type and
ensure that it comes from a freshly-opened
sealed container
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 is injurious to health.
General
1If any of the hydraulic components in the
braking system have been removed or
disconnected, or if the fluid level in the
reservoir has been allowed to fall appreciably,
it is inevitable that air will have been
introduced into the system. The removal of all
this air from the hydraulic system is essential
if the brakes are to function correctly, and the
process of removing it is known as bleeding.
2Where an operation has only affected one
circuit (front or rear) of the hydraulic system,
then it will only be necessary to bleed the
relevant circuit. If the master cylinder has
been disconnected and reconnected, or the
fluid level has been allowed to fall
appreciably, then the complete system must
be bled.
3One of three methods can be used to bleed
the system.
Bleeding
Two-man method
4Gather together a clean jar and a length of
rubber or plastic bleed tubing which will fit the
bleed screws tightly. The help of an assistant
will be required.
5Remove the dust cap where fitted, and
clean around the bleed screw on the relevant
caliper or wheel cylinder, then attach the
bleed tube to the screw (see illustration). If
the complete system is being bled, start at the
front left-hand caliper.
6Check that the fluid reservoir is topped up
and then destroy the vacuum in the brake
servo by giving several applications of the
brake pedal.
7Immerse the open end of the bleed tube in
the jar which should contain two or three
inches of hydraulic fluid. The jar should be
positioned about 300 mm (12.0 in) above the
bleedscrew to prevent any possibility of air
entering the system down the threads of the
bleed screw when it is slackened.
2Brake hydraulic system
(conventional braking system)
- bleeding1General information and
precautions
10•2Braking system
2.5 Removing the dust cap from a wheel
cylinder bleed screw
Caution: Refer to the
precautions in Section 1.
Page 5 of 22
the caliper, and the caliper body is modified
accordingly. Also, plastic covers are fitted to
the caliper guide bolts (see illustrations).
22Procedures are unchanged from those
given above.
Rear disc pads
23Slacken the 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.
24The disc pads can be inspected through
the top of the caliper after removal of the
blanking spring clip. Check that the friction
material thickness is not less than the
minimum given in the Specifications.
25If any one of the pads has worn below the
specified limit, the rear pads must be renewedas an axle set (4 pads).
26To renew the pads, proceed as follows.
27Release the handbrake, and free the
handbrake cable from the suspension lower
arm by bending back the tangs.
28Where applicable, disconnect the wiring
to the disc pad wear sensor (see illustration).
29Unscrew and remove the bolt from the
forward caliper guide pin, while holding the
pin stationary with a spanner (see
illustration).
30Swing the caliper rearwards and lift out
the disc pads (see illustration). Do not
depress the brake pedal with the caliper
removed.
31Brush all dirt and dust from the caliper,
pads and disc, but do not inhale it as it may
be injurious to health. Scrape any corrosion
from the disc.32As the new pads will be thicker than the
old ones, the piston must be retracted into its
bore to accommodate the new thicker pads.
Retracting 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. Retract the
caliper piston by turning it clockwise. Ford
tool No 12-006 is designed for this purpose,
but a pair of circlip pliers or any similar tool
can be used instead (see illustration).
33Remove the backing paper from the new
pads, and fit them to the caliper.
34Further refitting is a reversal of removal,
bearing in mind the following points.
35If disc pads with wear sensors are fitted,
the pad with the sensor wire should be fitted
inboard.
36Repeat the procedure on the opposite
rear brake.
37On completion, switch on the ignition and
apply the footbrake hard several times to
settle the pads. Switch off the ignition, then
check and if necessary top-up the fluid level in
the reservoir. Check the operation of the
handbrake.
38Avoid 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.
Braking system 10•5
10
4.21a Later type front disc pad retaining
clip
4.32 Retracting the piston using circlip
pliers4.30 Lift out the disc pads
4.28 Rear disc pad wear sensor wiring clip
(arrowed)
4.29 Unscrewing the forward caliper guide
pin bolt
4.21b Removing a caliper guide bolt cover
- later type
4.20b Refitting the caliper retaining clip -
Teves caliper4.20a The clip on the back of the inboard
disc pad fits into the piston recess - Teves
caliper
Page 10 of 22
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.
Page 11 of 22
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.
Page 13 of 22
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.
Page 14 of 22
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.
Page 16 of 22
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.
Page 17 of 22
Refitting
9Commence refitting by offering the pump to
the mounting spigot, then reconnecting the
low pressure fluid hose.
10Refit and tighten the pump mounting bolt.
11Reconnect the high pressure fluid hose,
using new sealing washers on the banjo
union.
12Refit the accumulator, using a new O-ring.
13Reconnect the multi-plugs and the
battery.
14Refill the fluid reservoir, then switch on the
ignition and allow the pump to prime itself.
Allow the pump to run for a maximum of two
minutes at a time then leave it for ten minutes
to cool down.
15On completion, bleed the complete
hydraulic system and check for leaks around
all disturbed components.
Note: To remove the pressure switch from the
hydraulic unit in situ, Ford tool No 12-008 or a
locally made equivalent will be required. The
switch may be removed without special tools
after removing the hydraulic unit complete or
the pump above. A new O-ring must be used
when refitting the switch.
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 multi-plug from the switch,
then unscrew and remove the switch.
Refitting
4Refit the switch using a new O-ring.
Position the plastic sleeve so that the drain
hole faces the pump motor, then tighten the
switch (see illustration).
5Reconnect the multi-plug and the battery.
6On completion, bleed the complete
hydraulic system and check for leaks around
all disturbed components.
Removal
1Disconnect the battery negative lead.
2Depressurise the hydraulic system by
pumping the brake pedal at least 20 times, or
until it becomes hard.
3Apply the handbrake, and slacken the
left-hand front wheel nuts. Jack up the front of
the vehicle and support on axle stands (see
“Jacking and Vehicle Support”).Remove the
left-hand front wheel.
4Remove the plastic liner from under the
wheel arch.
5Prepare a suitable container to catch spilt
fluid, clean around the unions on the valve
block, then unscrew and disconnect the fluid
pipes (see illustration). Plug the open ends of
the pipes and valve block to prevent fluid
leakage and dirt ingress. If fluid is accidentally
spilt on the paintwork, wash off immediately
with cold water.
6Disconnect the multi-plug and the earth
strap from the valve block.
7Working through the wheel arch, unscrew
the three nuts which secure the valve block
mounting bracket (see illustration).8Remove the valve block and mounting
bracket, taking care not to spill brake fluid on
the paintwork.
9No further dismantling of the valve block is
possible, but the pressure regulating valve in
the rear brake pipe union can be renewed if
desired.
Refitting
10Refitting is a reversal of removal.
11On completion, bleed the complete
hydraulic system and check for leaks around
all disturbed components.
Removal
1Disconnect the battery.
2Working inside the vehicle, prise out the
facia trim panel from the passenger’s side.
Remove the insulation.
3To remove the now exposed module, push
it as necessary to release the retaining catch.
21Computer module (ABS)
- removal and refitting
20Valve block (ABS) -removal
andrefitting
19Hydraulic unit pressure switch
(ABS) - removal and refitting
Braking system 10•17
10
20.5 Valve block and associated
components - ABS
A Bracket screws
B Adapter plate
C valve blockD Multi-plug
E Earth strap
anchor point
19.4 Refit the pressure switch with the
drain hole (arrowed) in the plastic sleeve
facing the pump motor - ABS18.5 Hydraulic unit pump mounting bolt -
ABS
20.7 Unscrewing the valve block mounting
bracket nuts (arrowed) - ABS
Caution: Refer to the
precautions in Section 1.
Caution: Refer to the
precautions in Section 1.
Page 19 of 22
Removal
1Chock the front wheels, jack up the rear of
the vehicle and support on axle stands (see
“Jacking and Vehicle Support”).
2The load apportioning valve is located on
the right-hand side of the vehicle underbody
above the axle.
3Remove the spring clip and clevis pin, and
detach the spring from the valve operating
lever (see illustration).
4Place a suitable container beneath the
valve to catch spilt fluid, then unscrew the
union nuts and disconnect the fluid pipes.
Plug the open ends of the pipes and valve to
prevent fluid leakage and dirt ingress.
5Unscrew the three securing nuts and bolts
from the valve mounting bracket, and remove
the valve assembly (see illustration).
Refitting
6Refitting is a reversal of removal, but note
that the fluid inlet pipe from the master cylindermust be connected to the lower valve port, and
the fluid outlet pipe to the rear brakes must be
connected to the upper valve port.
7On completion, bleed the rear hydraulic
circuit and check the valve adjustment.
Models before mid-April 1989
1The vehicle must be unladen, at normal
kerb weight (a full tank of petrol, but no driver
or load).
2With the vehicle standing on its roadwheels,
remove the spring clip and clevis pin, and
detach the spring from the valve operating
lever.
3Loosen the locknut on the abutment block
at the bottom of the spring (see illustration).
4Slide the spring through the grommet in the
bracket on the axle, until the correct “X”
dimension is obtained between the centre of
the spring eye and the centre of the valve
operating lever eye (see illustration).
5Hold the spring in position, slide the
abutment block against the underside of the
grommet, and tighten the locknut.
6Attach the free end of the spring to the
valve operating lever, and refit the clevis pin
and spring clip.
Models from mid-April 1989
7The procedure is as described above, but
note that the dimension “X” has been revised
to 92.0 mm (3.6 in) with the vehicle unladen at
normal kerb weight.
Removal
1To remove a flexible hose, always free it
from any mounting bracket(s) first by prising
out the U-shaped retaining clip, and then
using two close-fitting spanners to disconnect
the hose-to-rigid pipe union (see illustration).
2Once disconnected from the rigid pipe, the
flexible hose may be unscrewed from the
caliper or wheel cylinder union, as applicable.
Refitting
3When reconnecting pipe or hose fittings,
note that the seal is made at the swaged end
of the pipe, so do not continue to tighten a
union if it is tight, yet still stands proud of the
surface into which it is screwed.
26Brake fluid pipes and hoses
- removal and refitting25Load apportioning valve
(P100 models) - adjustment
24Load apportioning valve
(P100 models) - removal and
refitting
Braking system 10•19
10
25.3 Loosen the locknut (arrowed) on the
abutment block
26.1 Flexible hose-to-rigid pipe union. U-shaped retaining clip
arrowed25.4 Load apportioning valve adjustment
X = 77.0 mm (3.0 in) with vehicle unladen at normal kerb weight
24.5 Load apportioning valve securing
bolts (arrowed)24.3 Remove the spring clip (arrowed) and
clevis pin from the valve operating lever
Caution: Refer to the
precautions in Section 1.
Caution: Refer to the
precautions in Section 1.