brake fluid JAGUAR X308 1998 2.G Repair Manual

Power Brake Actuatio
n - Brake Boos
ter and Brake Master Cylinder
Re
moval and Installation
Remov

al
• C
AUTIONS:
Replacement of nuts and bolts: Various thread-locking de vices are used on nuts and bolts throughout the vehicle.
These devices restrict the number of times a nut or bolt can be used. See section 100-00 for information.
Remove brake fluid spilla ge immediately from paint work, with clean water.
1. Position vehi
cle on a four-post lift.
2. Move driver's seat fully rearward.
3. Open engine compartment and fit paint work protection covers
to fenders.
4. Disconnect battery ground cable (IMPORTANT, see operation
86.15.19 for further information).
5. Remove engine compartment rear cover. Refer to operation
76.11.35.
6. Remove pedal housing, brake booster and master cylinder
assembly. Refer to operation 70.35.39.
7. Remove reservoir filler cap and po ur residual brake fluid into a
container. Refit cap.

8. R
emove the clevis pin connecting the brake pedal to the
master cylinder push-rod fork.
1. Remove grommets from access holes.
2. Remove retaining clip.
3. Remove clevis pin.

9. Re
position the brake pedal to access the nuts securing the
brake booster to the pedal housing.
1. Remove pivot pin nut.
2. Remove pivot pin.
Reposition brake pedal.
10
.
Remove brake booster from pedal housing.
1. Remove grommet from access hole.
2. Remove nuts.

Anti-Lock Control -
Lubri
cants, Fluids, Sealants and Adhesives
Torques
Brake Tube, Hoses and Bracket Torques
CAUTI
ON: Replacement of
nuts and bolts: Various thread-locking devices are used on nuts and bolts throughout the
vehicle. These devices restrict the number of times a nut or bolt can be used. See section 100-00 for information.


UnitS
pecification
Brake flu

id
ITT Supe
r Dot 4
Com

ponent
Nm
Bol

t - front wheel speed sensor
8-
10
Bolt

- rear wheel speed sensor
8-
10
Bo

lt - hydraulic control unit to bracket
8-
10
Bolt -

hydraulic control unit bracket to body
10
-14
Hub rotor nut2

70-330
Com

ponent
Nm
Bleed n

ipple - front
4-
6
Bleed n

ipple - rear
8-1
1
Hose to fr

ont caliper
10
-14
Hose banjo to rear caliper -

bolt
30
-40
M1

0 hose locknut
15
-20
M10

brake tube female-nut
13
-17
M10

brake tube male-nut
13
-17
M12

brake tube male-nut
15
-20
M18

brake tube male-nut
22
-28
Brake tube clip retention

-bracket to body
4-
6

The brake
control modulator comprises:
a A

BS/TCCM
a h

ydraulic control unit,
an electrically driven hydrau

lic pump,
two low pressure accumulato

rs and damping chambers.
ABS/TCCM


The AB
S/TCCM is integrated with the hydrau
lic control unit. It houses the solenoids that operate the hydraulic control unit's
input and return valves; the valve stems locate into the ABS/TCCM's solenoids. There is no electrical connection between
the ABS/TCCM and the hydraulic control unit.
The ABS/TCCM constantly monitors the brake electronic system by passing self-checking electrical pulses around the circuit.
The self check procedures carried-out by the ABS/TCCM are listed below:
1. 1. Monitoring of the operating voltage: the control mo dule will shut-down should the voltages not be
(approximately) in the range of 9 to 19V.
2. 2. The pump is monitored for volt age supply and voltage feedback.
3. 3. Monitoring for disturbance, where a failure may be caus ed by external radio frequency interference, internal
leakage current, defective valve transistor or a faulty valve.
4. 4. Internal controller failure, de tected by a RAM and ROM test.
5. 5. The controller area network (CAN) micr o-controller checks for correct operation of the communication network
and performs a RAM self-check.
CAUTION: Disconnection of ABS/TCCM connectors may introduce other fault codes. Following rectification and
reconnection, ensure that no induced codes exist.
5.
Signals processed by the ABS/TCCM are also sent to the CAN for vehicle use, such as the instrument cluster speed display,
cruise control and stability/traction control.
Hydraulic Control Unit

Control of
the fluid pressure to
the front and rear brakes is by means of the valves contained in the hydraulic control unit.
The valves are operated by solenoids housed in the ABS/TCCM.
Hydraulic Pump
The
hydraulic pump is integrated
with the hydraulic control unit.


Bra
ke Control Modulator

It is a reciprocating two
-circuit pu
mp in which one brake circuit is as signed to each pump circuit.
It supplies th
e fluid pressure and vo
lume to supply the brake circuits under ABS and Traction control.
The pump is driven by an electri
c motor, with the pump
housing incorporating two lo w pressure accumulators and
damping chambers for each brake circuit.
The ac cu
mulator stores the pressure and smooths out the output pu
lses from the pump.
ABS Warning Lamp
The sys
tem will be set in a fail-safe mode if a problem is de
tected; a warning lamp on the instrument panel will notify the
driver there is a problem.
Anti-Lock Braking Sy
stem (ABS)
The AB
S components are combined with
an hydraulic booster and a tandem master cylinder to provide a two circuit braking
system. The system comprises, four wheel speed sensor s, a brake control modulator and an ABS warning lamp.
Should a wheel start to lock-up during braking a signal tr ansmitted from the wheel speed sensor to the brake control
modulator will start the hydraulic pump. The brake control modula tor will close the input valve of the line connected to the
locked-wheel to stop any increase in fluid pressure to the br ake caliper. If this fails to prevent the wheel locking, the
pressure in the caliper will be decreased by opening the return valve until th e wheel starts accelerating again. The fluid
pressure from the return va lve is directed into the low pressure accumulator, housed in the pump.
From the low pressure accumulator, fl uid is pumped through the damping cham ber to the brake master cylinder. The
pressure to the brake caliper will then be increased in small steps to maintain maximum adhesion between the tire and road
surface. This is achieved by closing the return valve, and opening the input valve and using the hydraulic pump to increase
the pressure.
Although the system senses all four wheels independently, the rear wheels are regulated as a pair. If a sensor on a rear
wheel detects a wheel decelerating rapidly, then the fluid pressure to both wheels is reduced. The fluid pressure is then
dictated by the wheel having the lowe st adhesion with the road surface.
The ABS system will be set in a fail-safe mode if a problem is detected; a warn ing lamp on the instrument panel will notify
the driver there is a problem. The brake system will still operate conventionally and with the same standard of performance
as a vehicle not equipped with ABS.
Automa tic Stability Control (ASC)

Th
e ASC utilizes the ABS sensing arrangement to provide the maximum traction force to propel the vehicle.
The ASC is switched on when the engine is started. The system can be switched off by pressing the 'ASC OFF' (the switched
is marked 'TRAC OFF' on vehicles fitted with traction control). The switch, which is situated in the center console switchpack,
lights up to warn that the system is sw itched off. An 'ASC' amber warning light flashes on the instrument panel when the
system detects a spinning wheel.
The ASC system uses engine intervention to reduce the torque delivered to the drive wheels to prevent them spinning.
Engine torque is re duced in three ways:
The
throttle is moved towards the closed position.
The ignition is retarded. F
u
el is cut-off at the cylinder injectors.
Wheel spin is detected by the wheel sp eed sensors and communicated to the AB S/TCCM. The ABS/TCCM uses information
from the controller area network (CAN) to calculate the torque that the engine should produce to stop the wheel spinning.
Torque reductions are then requested from the engine control module (ECM ) through the CAN. The throttle is then
positioned to provide the target torque, which has been calculated to prevent wheel spin. During the transient phase of
torque reduction the fuel is cut-off and th e ignition retarded Both the fuel cut-off an d ignition retard will be restored to
normal when the throttle is set to its new position.
The ASC uses a brake control modulator with six solenoid va lves: three normally open inlet valves and three normally

clos
ed outlet valves.
Traction Control
Trac

tion control has the same capabilities as ASC but with th
e added ability to actuate the brakes of the spinning wheel.
This enhances ASC by improving acceleration particularly on surfaces with uneven friction , e.g. one wheel on ice the other
on tarmac.
When wheelspin occurs, brake line pressure to the slipping wheel is generated, to operate that wheel's brake. The BCM
achieves this by closing the cut-off solenoid valve and oper ating the hydraulic pump. Brake fluid is then drawn from the
reservoir through the non-actuated mast er cylinder to the brake caliper.
A 'TRAC' amber warning light flashes on the instrument panel when the system detects a spinning wheel.
The traction control system uses a brake control modulator with nine solenoid valv es: four normally open inlet valves and
four normally closed outlet valves and one special isolating va lve. The outlet valves control the brakes of each each rear
wheel individually on the traction control system.
Rear Wheel Speed Senso
rs and ABS/TCCM Circuit Diagram

Anti-Lock Control - Anti-Lock Brake System (ABS) Module
Remo
val and Installation
Remov
a
l
• C
A
UTIONS:
Replacement of nuts and bolts: Various thread-locking de vices are used on nuts and bolts throughout the vehicle.
These devices restrict the number of times a nut or bolt can be used. See section 100-00 for information.
Remove brake fluid spilla ge immediately from paint work, with clean water.
Sp
ecial Tool(s)

Brake Pedal
H
old Tool
JDS 9013
1. Disc onne
ct battery ground cable (IMPORTANT, see operation
86.15.19 for further information).
2. Position vehicle on a four-post lift.
3. Open engine compartment and fit paint work protection covers
to fenders.

4. NOTE : Th
e following three pictorial procedures must be
carried-out to minimize brake fl uid loss when disconnecting the
brake tubes.
Open Left-Hand-Front and Left-H and-Rear caliper bleed nipples.
Connect a
bleed tube and co
ntainer to the calipers.
Op
en bleed nipples.

5. Depress and hold down brake pedal u s
ing special tool.
1. Position tool between brake pedal and seat frame.
2. Turn the tool wheel unti l the brake pedal is held
60mm down from its released position.
6. Tighten bleed nipples to:
Front caliper blee d nipple 4-6 Nm.

Rear
caliper bleed nip
ple 8-11 Nm.

Remove bleed tub
es and containers.

7. Disc
onnect electrical connectors from ABS/TCCM.
1. Pull plunger upwards.
2. Disconnect electrical connector.
3. Disconnect electrical connector
8. CAUTION: Remove brake flui d spillage immediately from
paint work, with clean water.
Position an absorbent cloth under neath the HCU to collect brake
fluid spillage.

9. NOTE
: To minimize brake fluid
loss, release the brake tubes
from the HCU in the order shown.
Release brake tubes from HCU.
1. Undo union nuts and re lease inlet brake tubes.
Install plugs to HCU inlet por
ts and brake tubes.
2. Undo union nuts and re lease outlet brake tubes.
Inst
all plugs to HCU outlet
ports and brake tubes.

10
.
Remove HCU from vehicle.
Re
move bolts.
T

aking care not to distort
brake tubes remove HCU.
11. Remove ABS/TCCM from the HCU.

In
stallation

Pla
ce the HCU on a work bench.
1. Disconnect electrical connector.
2. Remove bolts.
3. Remove ABS/TCCM.
12. Clean components and mating surfaces.

1. Install th e AB
S/TCCM to the HCU.
1. Install and tighten bolts.
2. Connect electrical connector.

2. Install HCU.
Takin g
care not to distort brake tubes position HCU into
bracket.
Install bolts and tighten to 8-1
0 Nm.

3. NOTE : To min
imize brake fluid lo
ss, install the brake tubes to
the HCU in the order shown.
Install brake tubes to HCU.
Re
move plugs from outlet HC
U ports and brake tubes.
1. Install and tighten outl et brake-tube union nuts.
Refer to Specification section 206-09 for torque
setting.
Re mo
ve plugs from inlet HC
U ports and brake tubes.
2. Install and tighten inlet brake-tube union nuts. Refer to Specification section 206-09 for torque setting.
4. Remove cloth from underneath HCU.
5. Connect electrical connectors to the ABS/TCCM.

Anti-Lock Control - Hydraulic Contro
l Unit (HCU)
Re
moval and Installation
Remov

al
• C
AUTIONS:
Replacement of nuts and bolts: Various thread-locking de vices are used on nuts and bolts throughout the vehicle.
These devices restrict the number of times a nut or bolt can be used. See section 100-00 for information.
Remove brake fluid spilla ge immediately from paint work, with clean water.
S
pecial Tool(s)

Brake Pedal

Hold Tool
JDS 9013
1. Disc
onnect battery ground cable (IMPORTANT, see operation
86.15.19 for further information).
2. Position vehicle on a four-post lift.
3. Open engine compartment and fit paint work protection covers
to fenders.

4. NOTE
: The following three pictorial procedures must be
carried-out to minimize brake fl uid loss when disconnecting the
brake tubes.
Open Left-Hand-Front and Left-H and-Rear caliper bleed nipples.
Connect
a bleed tube and co
ntainer to the calipers.
O
pen bleed nipples.

5. Depress and hold down brake pedal u
sing special tool.
1. Position tool between brake pedal and seat frame.
2. Turn the tool wheel unti l the brake pedal is held
60mm down from its released position.
6. Tighten bleed nipples to:
Front caliper blee d nipple 4-6
Nm.
Rear

caliper bleed nipple 8-11 Nm.

Remove bleed tube
s and containers.

7. Disc onne
ct electrical connectors from ABS/TCCM.
1. Pull plunger upwards.
2. Disconnect electrical connector.
3. Disconnect electrical connector
8. CAUTION: Remove brake flui d spillage immediately from
paint work, with clean water.
Position an absorbent cloth under neath the HCU to collect brake
fluid spillage.

9. NOTE : To min
imize brake fluid loss, release the brake tubes
from the HCU in the order shown.
Release brake tubes from HCU.
1. Undo union nuts and re lease inlet brake tubes.
Install plugs to HCU inlet por t
s and brake tubes.
2. Undo union nuts and re lease outlet brake tubes.
Instal
l plugs to HCU outlet
ports and brake tubes.

10 . R
emove HCU from vehicle.
Re
mo
ve bolts.
T
a
king care not to distort
brake tubes remove HCU.
11. Remove ABS/TCCM from the HCU.