1998 JAGUAR X308 light

Parking Brake and Ac
tu
ation - Parking Brake
Description an
d Operation

Parts List
The parking-brake hand lever is mounted on the transmission tunnel and incorporates the ratchet mechanism and release
button.
The front cable is routed from the hand lever, under the carpet through to an abutment bracket adjacent to the
transmission tunnel, and then connected to the relay lever. The relay lever is attached to a mounting plate by a center bolt
on which it rotates The relay lever mounting plate straddles the transmission tunnel, the plate is secured by four bolts. The
relay lever acts as a center pu ll system to transmit the force from the hand lever to the rear brakes shoes. The equalizer
which is positioned in the center of the rear brake cables balances the force that is applied to the rear brakes.
The rear brake cables are linked together: each cable passes through the rear hub carrier and connects to a brake shoe
expander lever. Application of the parking brake causes the rear cables to pu ll on the expander levers, the expander lever
mechanism rotates on a pivot pin to force the brake shoes outwards to contact the brake drums.
The parking brake cables are adjusted by the rotation of a nu t on the adjuster rod. The parking brake shoes are adjusted by
It
em
Par
t Number
De
scription
1—Hand Le

ver
2—Front Cable


3—R

elay Lever and Mounting Plate
4—Drivesh

aft Center Mounting
5—Cable Adjuster Rod


6—Equalize

r
7—Cable Connector
8—Rear Ca

ble RH
9—Rear Ca

ble LH
10—Warn

ing Light Switch and Harness
11—War

ning Lamp

Parking Brake and Actuation - P
arking Brake Control
Re
mo
val and Installation
Remov
a
l
W
A
RNING: BRAKE DUST, IF INHALED CAN DAMAGE YOUR
HEALTH. ALWAYS REMOVE BRAKE DUST USING A VACUUM
BRUSH. DO NOT USE A COMPRESSED-AIR LINE TO DISPERSE BRAKE DUST INTO THE ATMOSPHERE.
CAUTION: 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.
1. Position vehi cl
e on a four-post lift.
2. Release parking brake.

3. Releas
e tension on parking brake cable.
Slacken bu

t do not remove adjustment nut.

4. Releas
e parking brake cable.
Remo

ve clip.
Re
mo
ve clevis pin.
5. Remove driver seat for access . Refer to operation 76.70.01.
6. Remove trim from hand lever. Refer to operation 76.13.63.
7. Carefully reposition carpet from around hand lever for access.

8. Disconnect park ing-br
ake, warning-light switch connector.
9. Remove hand lever from vehicle.

I
nstallation

Re
move bolts.
R

emove lever.

10
.
Remove gasket.

11
.
Remove warning-light switch from lever.
R
emove screws.
Re

move switch.

1. Inst
all warning-light switch to hand lever.
Install and tigh

ten
screws to 3 Nm.
2. Install gasket to handbrake lever.

3. Instal
l hand lever to vehicle.
Install and tighten bolts to 2

2-28 Nm.

4. Connect park
ing-brake, warnin
g-light switch connector.
5. Reposition carpet.
6. Install trim to hand lever. Refer to operation 76.13.63.
7. Install driver seat. Refer to operation 76.70.01.
8. Make sure parking brake is in the released position.

9. Connect p a
rking brake cable.
Align ca
ble
.
Inst
al
l clevis pin.
Inst
al
l clip.
10. Adjust parking brake. Refer to operation 70.35.10.

Hydrau
lic Brake Actuation - Brake Pedal and Bracket
Re
mo
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.
In
stallation
1.
Position vehicl
e on a four-post lift.
2. Open hood and fit suitable pa intwork protection equipment.
3. Disconnect battery ground cabl e. (IMPORTANT, see 86.15.19
for further information).
4. Remove engine compartment rear cover. Refer to operation
76.11.35.
5. Remove pedal housing, brake booster and master cylinder
assembly. Refer to operation 70.35.39.
6. Remove brake booster and master cylinder assembly. Refer to
operation 70.50.18.

7. Remove brake wa
rning-light switch.
Remove n
u
t and bolt.
Slide sw

itch forward to release from locating tag.

8. Re
move throttle pedal assembly.
1. Remove and discard retaining wire.
2. Remove pivot pins.
3. Remove throttle pedal assembly.
4. Remove return spring.
9. Clean components and mating surfaces.
1. Apply grease to pivot pins.
2. Install throttle pedal assembly.
1. Align throttle assembly.

2
. Align return spring.
3. Install pivot pins.
4. Install retaining wire: bend ends of wire to secure
pivot pins.

3. Inst
all brake warning-light switch.
Inst

all switch onto locating tag.
Install and tigh

ten nut and bolt to 3Nm.
4. Install brake booster and master cylinder assembly. Refer to
operation 70.50.18.
5. Install pedal housing, brake booster and master cylinder
assembly. Refer to operation 70.35.39.
6. Bleed brake system. Refer to operation 70.25.03.
7. Install engine compartment rear cover. Refer to operation
76.11.35.
8. Connect battery ground cable. (IMPORTANT, see 86.15.19 for
further information).

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