1998 JAGUAR X308 brake booster

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).

Hydrau
lic Brake Actuation - Brake Pedal and Bracket, Brake Booster and
Brake Master Cylinder
Re mo
val and Installation
Remova

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.
1. Position vehi cl
e on a four-post lift.
2. Open engine compartment and fit paint work protection covers
to fenders.
3. Disconnect battery ground cable (IMPORTANT, refer to
operation 86.15.19 for fu rther information).
4. Remove engine compartment rear cover. Refer to operation
76.11.35.

5. Reposi
tion the mounting bracket of the cruise control vacuum-
valves for access (if installed).
R e
move screws.
Reposition bracket.


6. Disc
onnect low-level warning connector from master cylinder.
7. Disconnect vacuum pipe from brake booster.
1. Disconnect pipe.
2. Remove and discard seal.

In
stallation

Pull cabl
e from
pedal housing.

13 . Remove pedal h
ousing, brake
booster and master cylinder
assembly from vehicle.
F rom
driver footwell, remove nuts.
Carefull
y remove assembly.

14 . Remove an
d discard gask
et from pedal housing.
15. Clean components and mating surfaces.

1. Inst al
l gasket to pe
dal housing assembly.
2. CAUTION: Make sure no pipe s or cables become trapped
when fitting the pedal housing assembly.

Install peda
l housing to vehicle.
Make sure ped

al housing apertu
re is positioned correctly.
Inst
all and tighten nuts to 15-20 Nm.
3. Position cloth underneath master cylinder to collect brake fluid
spillage.

4. Inst
all brake tubes to master cylinder.
Re

move plugs.
Connect

and tighten brake tubes. Refer to Specification
section 206-06 for torque setting.
R
emove cloth from underneath master cylinder.

5. Con
nect throttle cabl
e to pedal housing.
Inst
all cable to grommet.
Inst

all cable to
pedal housing.

6. Conne
ct throttle inner ca
ble to pedal grommet.
7. Connect vacuum pipe elbow to brake booster.
1. Install new seal.
2. Connect pipe.

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.