lamp JAGUAR X308 1998 2.G User Guide

Front Disc Brake - Front Disc Brake
Description and Operation


The brake disc is mounted on the wheel studs and is clamped between the wheel and hub. Cooling ducts run through the
center of the brake disc to provide the required ventilation to keep the disc cool under operating conditions.
The caliper carrier, which is se cured to the vertical link by two bolts, carries the single-pis ton caliper housing. The caliper
housing is secured to the caliper carrier by two guide-pins and an anti-rattle spring. When the brakes are applied the
caliper-housing piston pushes th e brake pad in front of it, towards the brake di sc. This movement forces the caliper housing
to move along the guide-pins, in the oppo site direction of the piston, to apply the second brake pad. The brake disc is
therefore gripped between the two pads. As brake pressure is increased the grip on the brake disc is increased to slow-down
the rotation of the road wheel.
The disc brakes requ ire no adjustment.
It
e
m
Par
t
Number
De
scr
iption
1—B
r
ake Disc
2—Caliper Housin
g
3—Caliper Carrier
4—Brake Pads
5—Guide P i
ns
6—Du
st
Covers
7—An
ti
-rattle Spring
8—Du
st
Shield
9—Brake Hos
e

10—Bleed Nipp
le

• C
AUTIONS:
The Brembo caliper is aligned to the brak e disc when it is first installed to the vehicle, therefore, care must be taken
not to disturb this alignment. When removi ng the caliper; remove the bolts that secure the anchor bracket to the vertical
link only. DO NOT loosen any other caliper bolts.
Do not loosen bolts securing brake disc to disc mounting.
Brembo calipers and discs provide higher -performance braking using the existing hydraulic braking system. The brakes are
installed to the vehicle using unique vertical links, hubs, hydraulic hoses and disc shields.
The front brake disc consists of a ventilated, cross-drilled disc, bolted to a disc carrier. The disc assemb ly is mounted on the
wheel studs and clamped be tween the wheel and hub.
A unique feature of the front disc is th e slanted (non radial) ventilation webs which lean the opposite-way to the disc's
direction of rotation. This design enables he at generated by the disc to be dispersed by air entering at the disc's center and
being forced outwards through the cooling ducts.
Due to the use of fixed calipers in place of the standard floating caliper, certain lateral dimensions on the vertical link and
It
em
Par
t Number
De
scription
1—B

rake Disc
2—Caliper


3—Anch

or Bracket
4—Anchor Pl

ate to Vertical Link - Bolts
5—Brake Pad

s
6—Guide P

ins
7—Anti-r

attle Spring
8—Di

sc Shield
9—Brake Hos

e
10—Bleed Nipp

les


Front Disc Brake—
Brembo

Rear
Disc Brake - Rear Disc Brake
Description an
d Operation

The brake disc is mounted on the wheel studs and is clamped between the wheel and hub. Cooling ducts run through the
center of the brake disc to provide the required ventilation to keep the disc cool under operating conditions.
The caliper carrier, which is se cured to the hub carrier by two bolts, carries the single-piston caliper housing. The caliper
housing is secured to the caliper carrier by two guide-pins and an anti-rattle spring. When the brakes are applied the
caliper-housing piston pushes th e brake pad in front of it, towards the brake di sc. This movement forces the caliper housing
to move along the guide-pins, in the oppo site direction of the piston, to apply the second brake pad. The brake disc is
therefore gripped between the two pads. As brake pressure is increased the grip on the brake disc is increased to slow-down
the rotation of the road wheel.
The disc brakes requ ire no adjustment.
It
em
Par
t Number
De
scription
1—B

rake Disc
2—Caliper Housin

g
3—Caliper Carrier
4—Brake Pad

s
5—Guide P

ins

6—Du
st Covers
7—An

ti-rattle Spring
8—Du

st Shield
9—Brake Hos

e
10—Bleed Nipp

le

CAUTI O
N: The Brembo caliper is aligned to
the brake disc when it is first installed to the vehicle, therefore, care must
be taken not to disturb this alignment. When removing the ca liper; remove the bolts that secure the anchor bracket to the
hub carrier only. DO NOT loos en any other caliper bolts.
Brembo calipers and discs provide higher -performance braking using the existing hydraulic braking system. The brakes are
installed to the vehicle using unique hub carr iers, hubs, hydraulic hoses and disc shields.
The rear brake disc is a single piece co nstruction which is ventilated and cross-drilled. The disc is mounted on the wheel
studs and is clamped between the wheel and hub. Cooling ducts run through the ce nter of the brake disc to provide the
required ventilation to keep the disc cool under operating conditions.
Modified disc shields are installed to accommodate the larger diameter discs.
Due to the use of fixed calipers in place of the standard floating caliper, certain lateral dimensions on the hub carriers and
hubs are critical to achieve correct cleara nce and operation of the brakes. Therefore special hub carriers and hubs set within
a certain tolerance are inst alled with Brembo brakes.
The four cylinder brake caliper is rigidly attached to the vert ical link via an anchor bracket. The caliper is a split assembly
with each side of the caliper, housing two pistons. The two-pairs of opposed pistons act direct ly on the brake pads mounted
one each side of the disc.
It e
m
Par
t
Number
De
scr
iption
1—Brake D
i
sc
2—Caliper Housin
g
3—Anchor Bracke
t
4—Anchor Bracket to H
u
b Carrier - Bolts
5—Brake Pads


6—Guide Pi

ns
7—An
ti
-rattle Sprin
g
8—Di
sc
Shield
9—Brake Hos
e

10—Bleed Nipp
les

Rear Disc Brake - Brembo

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

means of a manual adjustment
mechanism
at each set of shoes. Refer to General Procedur es in section 206-05.
If the vehicle is driven above 5 km/h with the parking brake applied, a warning lamp and text message will appear on the
message center. The message clears when the brake is released or the speed drops below 3 km/h.
Parking Brake Shoe Arrangement

The adjuster mech
anism enables manual
adjustment of the brake shoes.
Retai
ning pins keep the shoes in contact with the dust shield.
The brake

shoes locate into the expander lever and the adjuster mechanism.
R
e
turn springs retr
act the brake shoes when the parking brake is released.
Th
e expander lever mechanism moves the brake shoes outwar
ds, in contact with the brake drum when the parking
brake is applied.


It e
m
Par
t
Number
De
scr
iption
1—Adjust
er Me
chanism
2—R
e
taining Pins
3—Brake Sh
oe
s
4—Upper
Return
Spring
5—Lower Return Spring
6—Expander

Lever Mechanism

Hydraulic Br
ake Actuation -
Hydraulic Brake Actuation
Description and Operation

The hydraulic brake system is split in to two independent circuits: the primary ci rcuit operates the front brakes and the
secondary circuit operates the re ar brakes. This type of system prevents comple te brake failure in the event of a brake tube
fracture.
The hydraulic brake system consists of the following components:

Ite
m
Descr
iption
1Pedal Housi

ng / Booster - refer to 206-07
2Vacu

um Hose - refer to 206-07
3Mast
er Cyl
inder / Reservoir
4Primary Brake Circu
i
t
5Secon
dary Brake Circuit
6Hydrauli c
Pump / Motor Unit - refer to 206-09
7ABS/Traction

Control Control Modu
le (ABS/TCCM) - refer to 206-09
8Hydraulic Cont
rol Unit (HCU) - refer to 206-09
6/
7/
8
Br
ak
e Control Modulator
9Brake
Di
sc - refer to 206-03 or 206-04
10Brake
Cali
per - refer to 206-03 or 206-04
11W
h
eel Speed Sensor - refer to 206-09
12ABS Warning Lamp -
refer to 206
-09
13Brake F
l
uid Level Warning-Lamp

The t
andem master cylinder contains two in
dependent pistons, fluid pressure to each brake circuit is controlled by its own
individual piston. Brake fluid is supplied to the master cylinder by the reservoir, which is divided into two sections to preve nt
total fluid loss should one of the circuits fail. A port situated at the bottom of each section of the reservoir supplies the f luid
to each piston.
The fluid reservoir has a fluid-le vel indicator switch installed, which operates when the fluid level is low, causing the brake
fluid level warning-lamp to illuminate.
Bra
ke Caliper
The brake
calipers are of the single piston
type. The caliper carrier, which is secured to the vertical link by two bolts, carr ies
the single-piston caliper housing. The cali per housing is secured to the caliper carrier by two guide-pins and an anti-rattle
spring. When the brakes are applied, the caliper-housing piston pushes the brake pad in front of it, to wards the brake disc.
This movement forces the calipe r housing to move along the guid e-pins, in the opposite direction of the piston, to apply the
second brake pad.
Br
embo Brake Caliper
The four
cylinder brake caliper is rigidly attached to the vert
ical link via an anchor bracket. The caliper is a split assembly
with each side of the caliper, housing two pistons. The two-pairs of opposed pistons act direct ly on the brake pads mounted
one each side of the disc.




Mast
er Cylinder and Reservoir

8. Posi
tion absorbent cloth underneath master cylinder to collect
brake fluid spillage.

9. Di
sconnect brake tubes from master cylinder.
Install plugs to brake tu

bes an
d master cylinder ports.

10
.
From driver footwell, disconne ct throttle inner cable from
pedal.
Re
move grommet.
Relea

se cable from pedal.

11
.
Disconnect stop-lamp-switch connector.
Move carpet.
Disc
onnect electrical connector.
12. From engine compartment, remo ve throttle cable from pedal
housing.
Re
lease grommet.

8. Conne ct
low-level warning connector to master cylinder.

9. Inst al
l cruise control vacuum-valves, mounting bracket.
Install and tigh
ten bolts.

10 . Conne
ct stop lamp switch connector.
Conne
ct
connector.
Re
posi
tion carpet.
11. Connect battery ground cable (IMPORTANT, see operation
86.15.15 for further information).
12. Bleed brake system. See operation 70.25.03.
13. Install engine compartment rear cover. Refer to operation
76.11.35.
14. Remove paint-work protection covers and close engine
compartment.

15 . Conne
ct battery ground cable (I
MPORTANT, refer to operation
86.15.19 for further information).