JAGUAR X308 1998 2.G Workshop Manual

Power Brake Actuation -
Lubri
cants, Fluids, Sealants and Adhesives
Brake Ratio
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.
B
rake 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
Fr

ont Brakes
6
5 per cent
Rear B

rakes
3
5 per cent
Com

ponent
Nm
N

ut - master cylinder to brake booster
21
-29
Nu

t - brake pedal pivot-pin to pedal housing
17
-23
Nu

t - brake switch to pedal housing
3
Nu

t - pedal housing to body
15
-20
Nu

t - brake booster to pedal housing
22
-28
Com

ponent
Nm
Bleed n

ipple - front
4-
6
Bleed n

ipple - rear
8-
11
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
Bolt -

3-way tube connector to body
9-
12

Power Brake Actuation - Brake Booster
Description and Operation


The brake b
ooster provides assi
stance by reinforcing the driver's effort when brakin g. The reinforced assistance
provided by the booster is proportional to the driver's effort applied to the brake pedal.
The brake force applied by
the driver is incr
eased by the booster in a ratio of 6.5:1.
Th
e vacuum used to operate the booster
is formed in the engine's intake manifold. The booster is connected to the
intake manifold by a hose.
The boost
er is fail-safe therefore, if a fault develops in
the vacuum unit, the braking system will still function.
However, the driver will have to apply a greater fo rce to the brake pedal to slow down the vehicle.


It e
m
Par
t
Number
De
scr
iption
1—Mas
t
er Cylinder / Reservoir - refer to 206-06
2—Booster

3—Pedal Box
- refer to 206-06
4—Vacuu
m
Hose
5—No
n
-Return Valve

Power Brake Actuatio
n - Brake Booster
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.
I
nstallation
1.
Position vehi
cle on a four-post lift.
2. Open engine compartment and fit paint work protection covers
to fenders.
3. Disconnect battery ground cable (IMPORTANT, see operation
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. R
emove nuts securing master cylinder to brake booster.

8. R
emove master cylinder from brake booster.
Re

move master cylinder.
Remove an

d discard seal.
9. Remove filler cap and empty residual brake fluid into a
container.
10. Clean components and mating surfaces.
1. Install master cylinder to brake booster.
Inst
all seal to master cylinder.

Instal
l master cylinder, make sure master cylinder rod
locates brake booster rod.

2. Inst al
l and tighten nuts to 21-29 Nm.
3. Install brake booster and master cylinder assembly. Refer to
operation 70.50.18.
4. Install pedal housing, brake booster and master cylinder
assembly. Refer to operation 70.35.39.
5. Install engine compartment rear cover. Refer to operation
76.11.35.
6. Reconnect battery ground cable (IMPORTANT, see operation
86.15.15 for further information).
7. Bleed brake system. Refer to operation 70.25.03.
8. Remove paint-work protection covers and close engine
compartment.

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.

In
stallation


11.
Remove brake
booster
from pedal housing.
Remo
ve nut.
Remove brake
booster
from pedal housing.
Remove brake
pedal
from pedal housing.

12 . Remove an
d discard gask
et from brake booster.
13. Clean components and mating surfaces.

1. Inst al
l gasket to brake booster.
2. Position brake pedal into pedal housing.
Apply grease to
push-rod fork.

Apply grease to
brake pedal pivots.
Position brake pedal.

3. Install brake pedal hou
s
ing to brake booster.
Wh
en installing brake booster,
make sure push-rod locates
inside brake pedal shaft.
1. Install and tighten nuts to 22-28 Nm.
2. Install grommet.

4. Install
final securing nut.
Tigh

ten nut to 22-28 Nm.

5. Install brake pedal to pedal h
ousing.
Install piv

ot pin.
Install nu

t and tighten to 17-23 Nm.

6. Inst
all clevis pin connecting
the brake pedal to the master
cylinder push-rod fork.
Apply grease to
the clevis pin.
1. Install clevis pin.
2. Install retaining clip.
3. Install grommets.
7. Install pedal housing, brake booster and master cylinder
assembly. Refer to operation 70.35.39.
8. Install engine compartment rear cover. Refer to operation
76.11.35.

9.
Reconn
ect battery ground cable (IMPORTANT, see operation
86.15.15 for further information).
10. Bleed brake system. Refer to operation 70.25.03.
11. Remove paint-work protection covers and close engine
compartment.

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

Anti-Lock Control - Anti-Lock Control
Description and Operation


Wheel Spe
ed Sensors
Each
wheel is monitored by a wheel speed se n
sor, to detect the speed of movement of
a toothed gear that is driven by the
wheel. Signal's generate d by the toothed gear passing th e sensor are sent to the ABS/TCCM to communicate the speed of
wheel rotation and any rapid change of wheel speed.
The frequency of the sinusoidal output voltag e signal from the sensor, is proportional to road wheel rotational speed and the
number of teeth on the toothed gear. The amplitude of the volt age is dependent upon the 'air gap' between the sensor and
toothed wheel, therefore it is important that this preset gap remains clear and undisturbed.
Ite
m
De
scr
iption
1Pe
dal Housi
ng / Booster - refer to 206-07
2Vac
u
um Hose - refer to 206-07
3Mas
t
er Cylinder / Reservoir - refer to 206-06
4Pri
m
ary Brake Circuit - refer to 206-06
5Sec

ondary Brake Circuit - refer to 206-06
6Hydraulic

Pump / Motor Unit
7ABS/Traction

Control Control Module (ABS/TCCM)
8Hydraulic Cont

rol Unit (HCU)
6/
7/
8
Br
ak
e Control Modulator
9Brake
Di
sc - refer to 206-03 or 206-04
10Brake
Cali
per - refer to 206-03/206-04
11Wh
ee
l Speed Sensor
12ABS Warning Lamp
13Brake
Fl
uid Level Warning-Lamp - refer to 206-06