1998 JAGUAR X308 bleed

Comp
onent Tests
Bra
k
e Booster
1.
1. Chec k all
hoses and connections. All unused vacuum connectors should be capped. Hoses and their connections
should be correctly secured and in good condition with no holes and no collapsed areas. Inspect the valve on the
brake booster for damage.
2. 2. Check the hydraulic brake system for leaks or low fluid.
3. 3. With the transmission in PARK, stop the engine and apply the parking brake. Pump the brake pedal several times
to exhaust all vacuum in the system.
4. 4. With the engine switched off and all vacuum in the system exhausted, appl y the brake pedal and hold it down.
Start the engine. If the vacuum system is operating, the brake pedal will tend to move downward under constant
foot pressure. If no motion is felt, the vacuum booster system is not functioning.
5. 5. Remove the vacuum hose from the brake booster. Manifold vacuum should be available at the brake booster end
of the hose with the engine at idle speed and the transm ission in PARK or NEUTRAL. Make sure that all unused
vacuum outlets are correctly capped, hose connectors are correctly secured and vacuum hoses are in good
condition. When it is established that manifold vacuum is available to the brake booster, connect the vacuum hose
to the brake booster and repeat Step 3. If no downward movement of the brake pedal is felt, install a new brake
booster.
6. 6. Operate the engine for a minimum of 10 seconds at a fast idle. Stop the engine and allow the vehicle to stand for
10 minutes. Then, apply th e brake pedal with approximately 89 N ( 20lb) of force. The pedal feel (brake
application) should be the same as that noted with the engine running. If the brake pedal feels hard (no power
assist), install a new valve and then re peat the test. If the brake pedal still feels hard, in stall a new brake booster.
If the brake pedal movement feels spongy, bleed the brak e system. For additional information, refer to General
Procedures in this section.
Bra k
e Master Cylinder
Usual
l
y, the first and strongest
indicator of anything wrong in the brake syst em is a feeling through the brake pedal. In
diagnosing the condition of the brake master cylinder, check pedal feel as evidence of a brake concern. Check for brake
warning lamp illumination and the brake fluid le vel in the brake master cylinder reservoir.
Normal Conditio
ns
The fo
llowing conditions are considered norm
al and are not indications that the brake master cylinder is in need of repair.
New bra
ke systems are designed to produc
e a pedal effort that is not as hard as in the past. Complaints of light
pedal efforts should be compared to the pedal effort s of another vehicle of the same model and year.
The fl
uid level will fall with brake pad wear.
Abnormal Conditions
•

NOTE: Prior to carrying out any diag
nosis, make sure the brake system warning indicator is functional.
Changes in the brake pedal feel or brake pedal travel are in dicators that something could be wrong in the brake system. The
diagnostic procedure and techniques use brake pedal feel, warning indicator illu mination and low brake fluid level as
indicators to diagnosing brake system co ncerns. The following conditions are cons idered abnormal and indicate that the
brake master cylinder is in need of repair:
Brake ped a
l goes down fast. Th
is could be caused by an ex ternal or internal leak.
Brake pedal goes down slowly
. This could be
caused by an internal or external leak.
Brak
e pedal is low or feels spongy. This condition may be ca
used by no fluid in the brake master cylinder, reservoir

Brake Sys
tem - General Informatio
n - Brake System BleedingVehicles
With: Standard Brakes
Gen e
ral Procedures
WARNING: WASH HANDS AFTER HANDLING BRAKE FLUID. IF BRAKE FLUID COMES INTO CONTACT WITH THE EYES,
FLUSH EYES WITH COLD RUNNING WATER. IF IRRITATION PERSISTS SEEK MEDICAL ATTENTION. IF BRAKE FLUID IS
TAKEN INTERNALLY, DRINK WATER AND INDUCE VO MITING. GET MEDICAL ATTENTION IMMEDIATELY.
CAUTION: Remove brake fluid spillage imme diately 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. NO
TE: Make sure the
brake-fluid level does not fall below the
fluid reservoir 'MIN' (minimum) mark when bleeding the brake
system.
Fill fluid reservoir to the 'MAX' (maximum) mark.

4. Prepare l e
ft-hand front, br
ake-caliper for bleeding.
Remove du
st cap.
Connect b
l
eed pipe
and fluid container to bleed nipple.
5. Bleed the brake.
1. Apply pressure to brake pedal
2. Open bleed nipple.
3. Fully depres s brake pedal.
4. Close bleed nipple.
5. Release brake pedal.
6. Wait two seconds to allow system to prime.
7. Repeat procedure until air- free brake fluid is expelled
from the caliper.
6. Tighten bleed nipple, see torque settings below.

Front caliper bleed
nipple: 4-6
Nm.
Rear caliper

bleed
nipple: 8-11 Nm.

7. F
ollowing the procedure below,
bleed the brakes in the order
shown:
1. Left-Hand Front,
2. Right-Hand Front,
3. Left- Hand Rear,
4. Right-Hand Rear.

8. CAUTI
ON: Remove brake flui
d spillage immediately from
paint work with clean water.
Fill fluid reservoir.
F
ill reservoir to the 'MAX' mark.
F

it filler cap.
9.
Start e
ngine.
10. Check for correct brake-pedal travel and pressure.
11. Apply brake pedal and check around vehicle for brake fluid
leaks.
12. Make sure brake fluid level is at the 'MAX' mark.

Brake Sys
tem - General Informatio
n - Brake System BleedingVehicles
With: High Performance Brakes
Gen e
ral Procedures
1. WARNINGS:
IF BRAKE FLUID IS TAKEN INTERNALLY, DRINK WATER
AND INDUCE VOMITING. GET MEDICAL ATTENTION
IMMEDIATELY.
WASH HANDS AFTER HANDLING BRAKE FLUID. IF BRAKE
FLUID COMES INTO CONTACT WITH THE EYES, FLUSH EYES
WITH COLD RUNNING WATER. IF IRRITATION PERSISTS SEEK
MEDICAL ATTENTION.
CAUTION: Remove brake flui d spillage immediately from
paint work with clean water.
Position vehicle on a four-post lift.
2. Op
en engine compartment and fit
paint work protection covers
to fenders.

3. NO
TE: Make sure the
brake-fluid level does not fall below the
fluid reservoir 'MIN' (minimum) mark when bleeding the brake
system.
Fill fluid reservoir to the 'MAX' (maximum) mark.

4. Pr
epare the left-hand front,
brake-caliper for bleeding.
Connect b
leed pipes an
d fluid containers to bleed nipples.
5. Bleed the brake.
1. Apply pressure to brake pedal.
2. Open caliper's outer bleed nipple.
3. Fully depres s brake pedal.

4
. Close bleed nipple.
5. Release brake pedal.
6. Wait two seconds to allow system to prime.
7. Repeat procedure until air- free brake fluid is expelled
from the bleed nipple.
8. Repeat procedure to ca liper's inner bleed nipple.

6. Tigh
ten bleed nipples to 12-16 Nm.

7. F
ollowing the procedure above,
bleed the brakes in the order
shown:
1. Left-Hand Front,
2. Right-Hand Front,
3. Left- Hand Rear,
4. Right-Hand Rear.

8. CAUTI
ON: Remove brake flui
d spillage immediately from
paint work with clean water.
Fill fluid reservoir.
F
ill reservoir to the 'MAX' mark.
F

it filler cap.
9.
Start e
ngine.
10. Check for correct brake-pedal travel and pressure.
11. Apply brake pedal and check around vehicle for brake fluid
leaks.
12. Make sure brake fluid level is at the 'MAX' mark.

Front Disc Brake -
Lubri
cants, Fluids, Sealants and Adhesives
Torques - Brembo Brakes
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
B

olt - anchor bracket to vertical link
18
0
Bo

lt - caliper to anchor bracket
DO
NOT REMOVE
Bleed n

ipple
12
-16
Hose u

nion to caliper
22
-26
Com

ponent
Nm
Bol

t - caliper carrier to vertical link
14
0
Guide

Pin - caliper housing to caliper carrier
25
-30
Com

ponent
Nm
Bleed n

ipple - front
4-
6
Bleed n

ipple - rear
8-1
1
Hose to fr

ont caliper
10
-14
Hose union to rear cal

iper - union 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

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