Ford Mondeo (petrol engines). Manual — part 104

Repeat the procedure at the other end of the
pipe, then release the pipe by pulling out the
clips attaching it to the body (see
illustrations). Where the union nuts are
exposed to the full force of the weather, they
can sometimes be quite tight. If an open-
ended spanner is used, burring of the flats on
the nuts is not uncommon, and for this
reason, it is preferable to use a split ring
(brake) spanner, which will engage all the
flats. If such a spanner is not available, self-
locking grips may be used as a last resort;
these may well damage the nuts, but if the
pipe is to be renewed, this does not matter.
7 To further minimise the loss of fluid when
disconnecting a flexible brake line from a rigid
pipe, clamp the hose as near as possible to
the pipe to be detached, using a brake hose
clamp or a pair of self-locking grips with
protected jaws.
8 To remove a flexible hose, first clean the
ends of the hose and the surrounding area,
then unscrew the union nuts from the hose
ends. Recover the spring clip, and withdraw
the hose from the serrated mounting in the
support bracket. Where applicable, unscrew
the hose from the caliper.
9 Brake pipes supplied with flared ends and
union nuts can be obtained individually or in
sets from Ford dealers or accessory shops.
The pipe is then bent to shape, using the old
pipe as a guide, and is ready for fitting. Be
careful not to kink or crimp the pipe when
bending it; ideally, a proper pipe-bending tool
should be used.

Refitting

10 Refitting of the pipes and hoses is a
reversal of removal. Make sure that all brake
pipes are securely supported in their clips,
and ensure that the hoses are not kinked.
Check also that the hoses are clear of all
suspension components and underbody
fittings, and will remain clear during
movement of the suspension and steering.
11 On completion, bleed the brake hydraulic
system as described in Section 15.

Warning: Brake fluid is
poisonous. Take care to keep it
off bare skin, and in particular
not to get splashes in your eyes.

The fluid also attacks paintwork - wash off
spillages immediately with cold water.
1 If the master cylinder has been
disconnected and reconnected, then the
complete system (both circuits) must be bled
of air. If a component of one circuit has been
disturbed, then only that particular circuit
need be bled.
2 Bleeding should commence on one front
brake, followed by the diagonally-opposite
rear brake. The remaining front brake should
then be bled, followed by its diagonally-
opposite rear brake.
3 There are a variety of do-it-yourself “one-
man” brake bleeding kits available from motor
accessory shops, and it is recommended that
one of these kits be used wherever possible,
as they greatly simplify the brake bleeding
operation. Follow the kit manufacturer’s
manuals in conjunction with the following
procedure. If a pressure-bleeding kit is
obtained, then it will not be necessary to
depress the brake pedal in the following
procedure.
4 During the bleeding operation, do not allow
the brake fluid level in the reservoir to drop
below the minimum mark. If the level is
allowed to fall so far that air is drawn in, the
whole procedure will have to be started again
from scratch. Only use new fluid for topping-
up, preferably from a freshly-opened
container.

Never re-use fluid bled from the

system.
5 Before starting, check that all rigid pipes
and flexible hoses are in good condition, and
that all hydraulic unions are tight. Take great
care not to allow hydraulic fluid to come into
contact with the vehicle paintwork, otherwise
the finish will be seriously damaged. Wash off
any spilt fluid immediately with cold water.
6 If a brake bleeding kit is not being used,
gather together a clean jar, a length of plastic
or rubber tubing which is a tight fit over the
bleed screw, and a new can of the specified
brake fluid (see Chapter 1 Specifications). The
help of an assistant will also be required.
7 Clean the area around the bleed screw on
the front brake unit to be bled (it is important

that no dirt be allowed to enter the hydraulic
system), and remove the dust cap. Connect
one end of the tubing to the bleed screw, and
immerse the other end in the jar, which should
be filled with sufficient brake fluid to keep the
end of the tube submerged.
8 Open the bleed screw by one or two turns,
and have the assistant depress the brake
pedal to the floor. Tighten the bleed screw at
the end of the downstroke, then have the
assistant release the pedal. Continue this
procedure until clean brake fluid, free from air
bubbles, can be seen flowing into the jar.
Finally tighten the bleed screw with the pedal
in the fully-depressed position.
9 Remove the tube, and refit the dust cap.
Top-up the master cylinder reservoir if
necessary, then repeat the procedure on the
diagonally-opposite rear brake.
10 Repeat the procedure on the remaining
circuit, starting with the front brake, and
followed by the diagonally-opposite rear
brake.
11 Check the feel of the brake pedal - it
should be firm. If it is spongy, there is still
some air in the system, and the bleeding
procedure should be repeated.
12 When bleeding is complete, top-up the
master cylinder reservoir and refit the cap.

Testing

1 To test the operation of the servo unit,
depress the footbrake four or five times to
dissipate the vacuum, then start the engine
while keeping the footbrake depressed. As
the engine starts, there should be a noticeable
“give” in the brake pedal as vacuum builds
up. Allow the engine to run for at least two
minutes, and then switch it off. If the brake
pedal is now depressed again, it should be
possible to hear a hiss from the servo when
the pedal is depressed. After four or five
applications, no further hissing should be
heard, and the pedal should feel harder.
2 Before assuming that a problem exists in
the servo unit itself, inspect the non-return
valve as described in the next Section.

Removal

3 Refer to Section 11 and remove the master
cylinder.
4 Disconnect the vacuum hose adaptor at the
servo unit by pulling it free from the rubber
grommet. If it is reluctant to move, prise it
free, using a screwdriver with its blade
inserted under the flange.
5 Unscrew the four nuts securing the servo
unit to the mounting brackets on the bulkhead
in the engine compartment.
6 On right-hand drive models, withdraw the
servo unit so that its studs are just clear of the
brackets. Have an assistant hold the brake
pedal depressed, then extract the spring clip

16 Vacuum servo unit -

testing, removal and refitting

15 Hydraulic system - bleeding

9•12 Braking system

14.6A Unscrewing a brake pipe union nut

using a split ring spanner

14.6B Pulling out a brake pipe mounting

clip

and remove the clevis pin securing the servo
unit pushrod to the pedal cross-link arm.
7 On left-hand drive models, unscrew the nut
securing the pedal trunnion to the servo unit
pushrod inside the passenger compartment.
The nut is located near the top of the pedal,
and is accessible through an access hole. For
improved access, remove the lower facia
panel first.
8 Withdraw the servo unit from the bulkhead,
and remove it from the engine compartment.
On left-hand drive models, take care not to
damage the bulkhead rubber grommet as the
pushrod passes through it.
9 Note that the servo unit cannot be
dismantled for repair or overhaul and, if faulty,
must be renewed.

Refitting

10 Refitting is a reversal of the removal
procedure. Refer to Section 11 for details of
refitting the master cylinder.

Removal

1 Depress the brake pedal four or five times,
to dissipate any remaining vacuum from the
servo unit.
2 Disconnect the vacuum hose adaptor at the
servo unit, by pulling it free from the rubber
grommet (see illustration). If it is reluctant to
move, prise it free, using a screwdriver with its
blade inserted under the flange.
3 Detach the vacuum hose from the inlet
manifold connection, pressing in the collar to
disengage the tabs, then withdrawing the
collar slowly.
4 If the hose or the fixings are damaged or in
poor condition, they must be renewed.

Testing

5 Examine the non-return valve for damage
and signs of deterioration, and renew it if
necessary. The valve may be tested by
blowing through its connecting hoses in both
directions. It should only be possible to blow
from the servo end towards the inlet manifold.

Refitting

6 Refitting is a reversal of the removal
procedure. If fitting a new non-return valve,
ensure that it is fitted the correct way round.

Removal

1 On non-ABS models, the two pressure-
control relief valves (sometimes referred to as
pressure-conscious reducing valves) are
located on the master cylinder outlets to the
rear brake line circuits.
2 Unscrew and remove the fluid reservoir filler
cap, and draw off the fluid - see Section 11.
3 Position some rags beneath the master
cylinder, to catch any spilled fluid.
4 Clean around the valve to be removed.
Hold the PCR valve stationary with one
spanner, and unscrew the hydraulic pipe
union nut with another spanner. Pull out the
pipe, and bend it slightly away from the valve.
5 Unscrew the PCR valve from the master
cylinder.
6 Note that the primary and secondary PCR
valves have different thread diameters, to
prevent incorrect fitment. The primary valve
has a 12 mm diameter thread, and the
secondary valve has a 10 mm diameter thread
(see illustration).

Refitting

7 Refitting is a reversal of the removal
procedure. On completion, bleed the
hydraulic system as described in Section 15.

Removal

1 On ABS models, the pressure-control relief
valves are located on the ABS hydraulic unit
(see illustration).
2 Disconnect the battery negative (earth) lead
(Chapter 5, Section 1).
3 Remove the air cleaner assembly as
described in Chapter 4.
4 Remove the engine air inlet duct and air
plenum chamber.
5 Disconnect the low fluid level warning
multi-plug from the brake fluid reservoir.
6 Unscrew and remove the brake fluid
reservoir filler cap, and completely seal the
top of the reservoir using cling film or
adhesive tape. This will reduce loss of fluid
when the PCR valve is removed.
7 Unscrew the master cylinder mounting
nuts, and carefully withdraw the cylinder from
the servo unit, leaving the brake pipes still
connected to it. Move the master cylinder
over to the left-hand side of the engine

compartment, to rest against the left-hand
suspension turret. (Throughout this manual,
left- and right-hand are as seen from the
driver’s seat.)
8 Unscrew the servo unit mounting nuts, and
move the unit to one side.
9 Position some rags beneath the ABS unit,
to catch spilled fluid.
10 Clean around the valve to be removed.
Hold the PCR valve stationary with one
spanner, and unscrew the hydraulic pipe
union nut with another spanner. Pull out the
pipe, and bend it slightly away from the valve.
11 Unscrew the PCR valve from the ABS
unit.

Refitting

12 Refitting is a reversal of the removal
procedure. On completion, bleed the
hydraulic system as described in Section 15.

19 Pressure-control relief valve

(ABS models) -
removal and refitting

18 Pressure-control relief valve

(non-ABS models) -
removal and refitting

17 Vacuum servo unit vacuum

hose and non-return valve -
removal, testing and refitting

Braking system 9•13

9

17.2 Removing the plastic adaptor from

the servo unit

18.6 Pressure-control relief valve

locations

1 Primary PCR valve (12 mm)
2 Secondary PCR valve (10 mm)

19.1 Pressure-control relief valve locations

on the ABS hydraulic unit

1 PCR valve, rear right brake circuit
2 Outlet, front left brake circuit
3 Inlet, from brake master cylinder secondary

circuit

4 PCR valve, rear left brake circuit
5 Outlet, front right brake circuit
6 Inlet, from brake master cylinder primary

circuit

Note: If any part of the ABS hydraulic unit is
defective, it must be renewed as an assembly.
Apart from the relay box (Section 22),
individual spare parts are not available.

Removal

1 Remove both pressure-control relief valves
as described in Section 19.
2 Identify the location of the remaining brake
hydraulic pipes on the ABS hydraulic unit,
then unscrew the union nuts and pull out the
pipes. Carefully bend the pipes away from the
hydraulic unit, to allow the unit to be removed.
3 Disconnect the multi-plugs from the
hydraulic unit. To disconnect the main 22-pin
multi-plug, push the locktab, then swivel the
multi-plug outwards and unhook it.

Right-hand drive models

4 Have an assistant hold the brake pedal
depressed, then extract the spring clip and
remove the clevis pin securing the servo unit
pushrod to the pedal cross-link arm.
5 Remove the vacuum servo unit from the
engine compartment.

Left-hand drive models

6 Unscrew the nut securing the pedal
trunnion to the servo unit pushrod inside the
passenger compartment. The nut is located
near the top of the pedal, and is accessible
through an access hole. For improved access,
remove the lower facia panel first.
7 Remove the vacuum servo unit, together
with the pushrod, from the engine
compartment. Take care not to damage the
rubber grommet in the bulkhead.

All models

8 Unscrew the pump mounting nut.
9 Raise the left-hand side of the ABS
hydraulic unit, then swivel the unit out of the
right-hand mounting. Take care not to lose the
bracket studs and insulator ring.

Refitting

10 Locate the insulator ring on the pump
end, and fit the stud cap to the insulator ring.
11 Lower the ABS hydraulic unit into
position, right-hand end first.
12 Fit the right-hand bracket studs onto the
insulators.
13 Lower the left-hand end of the ABS
hydraulic unit onto the bracket, then fit and
tighten the pump mounting nut.

Left-hand drive models

14 Locate the vacuum servo unit and
pushrod on the bulkhead bracket, taking care
not to damage the rubber grommet.
15 Insert the pushrod in the pedal trunnion,
and tighten the nut.
16 Refit the lower facia panel if it was
removed.

Right-hand drive models

17 Locate the vacuum servo unit and
pushrod on the bulkhead bracket.
18 Refit the clevis pin and spring clip
securing the servo unit pushrod to the pedal
cross-link arm.

All models

19 Reconnect the multi-plugs to the
hydraulic unit.
20 Reconnect the brake pipes to the
hydraulic unit, and tighten the union nuts.
21 Refit both pressure-control relief valves,
with reference to Section 20.

Testing

1 Checking of the sensors is done before
removal, connecting a voltmeter to the
disconnected sensor multi-plug. Using an
analogue (moving coil) meter is not practical,
since the meter does not respond quickly
enough. A digital meter having an AC facility
may be used to check that the sensor is
operating correctly. To do this, raise the
relevant wheel then disconnect the wiring to
the ABS sensor and connect the meter to it.
Spin the wheel and check that the output
voltage is between 1.5 and 2.0 volts,
depending on how fast the wheel is spun.
Alternatively, an oscilloscope may be used to
check the output of the sensor - an alternating
current will be traced on the screen, of
magnitude depending on the speed of the
rotating wheel.
2 If the sensor output is low or zero, renew
the sensor.

Removal

Front wheel sensor

3 Apply the handbrake, jack up the front of
the vehicle and support it on axle stands.
Remove the relevant wheel.
4 Unscrew the sensor mounting bolt located
on the steering knuckle, and withdraw the
sensor (see illustrations).
5 Remove the sensor wiring loom from the

support brackets on the front suspension
strut and wheel arch.
6 Prise out the stud clips, and remove the
Torx screws and screw clips holding the wheel
arch liner in position. Withdraw the liner.
7 Disconnect the multi-plug, and withdraw
the sensor and wiring loom.

Rear wheel sensor

8 Chock the front wheels, and engage 1st
gear (or “P”). Jack up the rear of the vehicle
and support it on axle stands. Remove the
relevant wheel.
9 Unscrew the sensor mounting bolt, located
on the brake backplate (drum brakes) or rear
suspension knuckle (disc brakes), and
withdraw the sensor.
10 On disc brake models, prise out the stud
clips, and remove the Torx screws and screw
clips holding the wheel arch liner in position.
Withdraw the liner.
11 Disconnect the sensor wiring loom from
the supports on the rear suspension strut (or
knuckle) and wheel arch.
12 Working inside the vehicle, lift the rear
seat cushion, then disconnect the multi-plug
for the sensor wiring loom (see illustration).
13 Withdraw the sensor and wiring loom
through the rubber grommet in the rear floor.

Refitting

Front and rear wheel sensors

14 Refitting is a reversal of the removal
procedure.

Removal

1 Disconnect the battery negative (earth) lead
(Chapter 5, Section 1).
2 Detach the vacuum hose from the inlet
manifold connection, pressing in the collar to
disengage the tabs, then withdrawing the
collar slowly.
3 To improve access, free the heater hose
from its retaining clips, and position it clear of
the relay box.
4 Disconect the wiring connector(s) from the
relay box and, where necessary, the speed
sender unit.

22 ABS relay box -

removal and refitting

21 ABS wheel sensor -

testing, removal and refitting

20 ABS hydraulic unit -

removal and refitting

9•14 Braking system

21.4 Unscrew the mounting bolt and

remove the ABS sensor

21.12 Rear ABS sensor wiring multi-plug

located beneath the rear seat

5 Slacken and remove the four Torx retaining
screws, and withdraw the relay box from the
hydraulic unit (see illustration).

Refitting

6 Refitting is a reversal of the removal
procedure. Do not overtighten the relay box
retaining screws, as the plastic is easily
cracked

Removal

1 Disconnect the battery negative (earth) lead
(Chapter 5, Section 1).
2 Using a small screwdriver and a suitable
pad (to protect the facia), prise out the TCS
inhibitor switch from the facia.

3 Disconnect the multi-plug from the switch,
and withdraw the switch.

Refitting

4 Refitting is a reversal of the removal
procedure.

Removal

1 The TCS throttle actuator is located in the
front right-hand corner of the engine
compartment. First disconnect the battery
negative (earth) lead (Chapter 5, Section 1).
2 Disconnect the wiring multi-plug at the TCS
actuator (see illustration).
3 Prise off the motor cover (see illustration).

4 Turn the upper throttle control segment, to
provide some play in the accelerator cable
leading to the throttle housing, then
disconnect the cable by unhooking the end
stop. Release the cable from the motor
housing support (see illustrations).
5 Turn the lower accelerator control segment,
to provide play in the accelerator cable from
the accelerator pedal, then disconnect the
cable by unhooking the end stop. Release the
cable from the motor housing support (see
illustration).
6 Unscrew the mounting bolts, and lift out the
TCS throttle actuator (see illustration).

Refitting

7 Refitting is a reversal of the removal
procedure. Adjust the accelerator cables as
described in Chapter 4.

Removal

1 Disconnect the battery negative (earth) lead
(Chapter 5, Section 1).
2 Remove the lower facia panel, with
reference to Chapter 11.
3 Disconnect the wiring multi-plug from the
switch.
4 Rotate the switch anti-clockwise by a
quarter-turn, and withdraw it from the pedal
bracket (see illustration).

25 Stop-light switch -

removal and refitting

24 TCS throttle actuator -

removal and refitting

23 TCS inhibitor switch -

removal and refitting

Braking system 9•15

9

24.4B Releasing the cable from the motor

housing support

24.4A Disconnecting the accelerator cable

(arrowed) from the upper throttle control

segment

24.5 Disconnecting the accelerator cable

(arrowed) from the lower throttle control

segment

24.6 Removing the TCS actuator

22.5 Removing the ABS relay box

24.2 Disconnecting the multi-plug

(arrowed) at the TCS actuator

24.3 Removing the TCS motor cover

25.4 Removing the stop-light switch