water pump FORD SIERRA 1984 1.G Braking System Workshop Manual

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.

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.

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.