sensor FORD SIERRA 1986 1.G Braking System Workshop Manual

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

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.

8Open the bleed screw half a turn and have
your assistant depress the brake pedal slowly
to the floor and then, after the bleed screw is
retightened, quickly remove his foot to allow
the pedal to return unimpeded. Repeat the
procedure.
9Observe the submerged end of the tube in
the jar. When air bubbles cease to appear,
tighten the bleed screw when the pedal is
being held fully down by your assistant.
10Top-up the fluid reservoir. It must be kept
topped up throughout the bleeding
operations. If the connecting holes to the
master cylinder are exposed at any time due
to low fluid level, then air will be drawn into
the system and work will have to start all over
again.
11Assuming that the complete system is
being bled, the procedure described in the
preceding paragraphs should be repeated on
the front right-hand caliper followed by the
rear right-hand and left-hand wheel cylinders.
12On completion, remove the bleed tube,
and discard the fluid which has been bled
from the system unless it is required for bleed
jar purposes. Never re-use old fluid.
13On completion of bleeding, top-up the
fluid level in the reservoir. Check the action of
the brake pedal, which should be firm and free
from any “sponginess” which would indicate
that air is still present in the system.
With one-way valve
14There are a number of one-man brake
bleeding kits currently available from motor
accessory shops. It is recommended that one
of these kits should be used whenever
possible, as they greatly simplify the bleeding
operation and also reduce the risk of expelled
air or fluid being drawn back into the system.
15Proceed as described in paragraphs 5
and 6.
16Open the bleed screw half a turn then
depress the brake pedal to the floor and
slowly release it. The one-way valve in the
bleeder device will prevent expelled air from
returning to the system at the completion of
each stroke. Repeat this operation until clear
hydraulic fluid, free from air bubbles, can be
seen coming through the tube. Tighten the
bleed screw.
17Proceed as shown in paragraphs 11 to 13.
With pressure bleeding kit
18These too are available from motor
accessory shops and are usually operated by
air pressure from the spare tyre.
19By connecting a pressurised container to
the master cylinder fluid reservoir, bleeding is
then carried out by simply opening each bleed
screw in turn and allowing the fluid to run out,
rather like turning on a tap, until no air bubbles
are visible in the fluid being expelled.
20Using this system, the large reserve of
fluid provides a safeguard against air being
drawn into the master cylinder during the
bleeding operations.21This method is particularly effective when
bleeding “difficult” systems or when bleeding
the entire system at time of routine fluid
renewal.
22Begin bleeding with reference to
paragraphs 5 and 6 and proceed as described
in paragraphs 11 to 13.
1Keep the fluid reservoir replenished
throughout the bleeding operations.
2Remove the dust cap where fitted, and
clean around the bleed screw on the left-hand
front caliper. Fit a bleed tube to the screw and
immerse the open end in a jar containing
clean hydraulic fluid.
3Open the bleed valve one full turn and have
an assistant depress the brake pedal fully and
hold it down.
4Close the bleed valve and release the brake
pedal. Repeat the procedure until fluid ejected
from the end of the tube is free from air
bubbles.
5Repeat the operations on the right-hand
front caliper.
6Fit the bleed tube to the left-hand rear
caliper and open the bleed valve one full turn.
7Have an assistant depress the brake pedal
fully and hold it down.
8Switch on the ignition to position ll.
9Allow the fluid to bleed from the tube for at
least 15 seconds, when the fluid should be
free from air bubbles.
10Close the bleed valve.
11Release the brake pedal and wait for the
hydraulic pump to stop.
12Fit the bleed tube to the right-hand rear
caliper and open the bleed valve one full turn.
13Have your assistant depress the brake
pedal through half its travel and hold it there.
Allow the fluid to bleed from the tube for at
least 15 seconds, when the fluid should be
free from air bubbles.
14Close the bleed valve.
15Release the brake pedal and wait for the
hydraulic pump to stop then switch off the
ignition.
16Top-up the reservoir with clean fluid.
17When the hydraulic system is being bled
for the purpose of renewing the fluid at the
specified interval, as each caliper is bled,
operate the brake pedal continuously until
clean fluid is seen to enter the jar.
18When the hydraulic pump is running its
note will be heard to change once fluid has
purged through it. Do not allow the pump torun continuously for more than two minutes. If
it does run for a longer period, switch off the
ignition and allow the motor to cool for ten
minutes.
19On completion, discard the fluid which
has been bled from the system unless it is
required for bleed jar purposes. Never re-use
old fluid.
20Check the action of the brake pedal,
which should be firm and free from any
“sponginess”, which would indicate that air is
still present in the system.
Front disc pads
1The disc pad friction material can be
inspected for wear without removing the
roadwheels. Working beneath the vehicle,
insert a mirror between the caliper and the
roadwheel and check that the friction material
thickness is not less than the minimum given
in the Specifications.
2If any one of the pads has worn below the
specified limit, the front pads must be
renewed as an axle set (4 pads).
3To renew the pads, slacken the front
roadwheel nuts, apply the handbrake, then
jack up the front of the vehicle and support on
axle stands (see “Jacking and Vehicle
Support”). Remove the roadwheels. On P100
models, mark the position of the roadwheels
in relation to the wheel studs before removal.
4Proceed as follows according to model:
Girling caliper (1.3 and early 1.6 litre
models)
5Where applicable, disconnect the wiring to
the disc pad wear sensor.
6Unscrew and remove the bolt from the
upper caliper guide pin while holding the pin
stationary with a spanner (see illustration).
7Swing the caliper downwards and lift out
the disc pads. If the outboard pad is stuck to
4Disc pads -inspectionand
renewal
3Brake hydraulic system (ABS)
- bleeding
Braking system 10•3
10
4.6 Unscrewing the bolt from the upper
caliper guide pin - Girling caliper
Caution: Refer to the
precautions in Section 1.
Caution: The rear brake
hydraulic circuit may be under
considerable pressure, take
care not to allow hydraulic fluid
to spray into the face or eyes. Refer to the
precautions in Section 1.

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

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

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.

4Withdraw the module, and disconnect the
multi-plug (see illustration).
Refitting
5Refitting is a reversal of removal but on
completion check the operation of the ABS
warning lamp as described in the
manufacturer’s handbook.
Note: A new O-ring must be used when
refitting a sensor.
Front wheel sensor
1Apply the handbrake, loosen the relevant
front roadwheel nuts, then jack up the front of
the vehicle and support on axle stands (see
“Jacking and Vehicle Support”). Remove the
roadwheel.
2Working under the bonnet, unclip the ABS
wiring loom from the chassis side member,
and disconnect the wheel sensor wiring plug.
3Unscrew the mounting bolt and withdraw
the sensor (see illustration).
4Refitting is a reversal of removal, bearing in
mind the following points.
5Clean the bore in the hub carrier, and smear
the bore and the sensor with lithium based
grease.
6Use a new O-ring seal when refitting the
sensor.
Rear wheel sensor
7Chock the front wheels, loosen the relevant
rear roadwheel nuts, then jack up the rear of
the vehicle and support on axle stands.
Release the handbrake and remove the
roadwheel.
8Working inside the vehicle, lift up the rear
seat cushion, then remove the side kick panel
and fold the carpet forwards to gain access to
the wheel sensor wiring plug (see
illustrations).
9Remove the wiring plug from its clip, and
disconnect it.
10Prise out the floor panel grommet, then
feed the sensor wiring through the floor panel.
11Free the handbrake cable from its clip on
the suspension lower arm.12Where applicable, disconnect the wiring
to the disc pad wear sensor.
13Unscrew and remove the bolt from the
forward caliper guide pin, while holding the
pin stationary with a spanner.
14Swing the caliper rearwards to gain
access to the wheel sensor.
15Unscrew the bolt securing the sensor to
its mounting bracket.
16Refitting is a reversal of removal, bearing
in mind the following points.
17Clean the bore in the sensor mounting
bracket, and smear the bore and the sensor
with lithium based grease.
18Use a new O-ring seal when refitting the
sensor.
Removal
1The deceleration sensitive valve is located
on the left-hand side of the engine
compartment (see illustrations).
2Place 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. If fluid is
accidentally spilt on the paintwork, wash off
immediately with cold water.
3On early models, the valve is secured to the
mounting bracket on the inner wing by a
single bolt. Unscrew the bolt and remove the
valve.
4On later models, the valve is secured to the
mounting bracket by a clip. Remove the clip
and slide out the valve.
Refitting
5Refitting is a reversal of removal, but note
that the early type of valve must be fitted with
the cover bolts facing forwards, and the later
type of valve must be fitted with the smaller
diameter stepped end facing forwards.
6On completion, bleed the rear hydraulic
circuit.
23Deceleration sensitive valve
(all models with conventional
braking system)
- removal and refitting
22Wheel sensor (ABS)
- removal and refitting
10•18Braking system
21.4 Withdraw the module and disconnect
the multi-plug - ABS22.8a Remove the side kick panel
(securing screws arrowed) for access to
the rear wheel sensor wiring plug - ABS
23.1b Later type deceleration sensitive
valve23.1a Early type deceleration sensitive
valve
22.8b Rear wheel sensor wiring plug
(arrowed) - ABS
22.3 Unscrew the mounting bolt and
withdraw the front wheel sensor - ABS
Caution: Refer to the
precautions in Section 1.