1998 JAGUAR X308 pedal

Do t
he disc brake caliper pistons
and pins bind, leak or stick?
Yes INSTALL new calipers as necessary. TE ST the system for normal operation.
No GO to C4
.
C4: INSPECT BR
AKE DISCS
Check the brake discs fo

r excess
ive damage, thickness variatio n or runout. For additional
information, refer to General Procedures in this section.
1
D
oes excessive damage or runout exist?
Yes INSTALL new brake discs and brak e pads as necessary. TEST the system for normal operation.
No GO to C5
.
C5: INSPECT THE FRONT HU
B AND WHEEL BEARING ASSEMBLY
Check the fr

ont hub and wheel bearing assembly.
For additional information, refer toSection 204
-00

Su

spension System
- General
Information
. 1
Are th

e wheel bearings OK?
Yes GO to C6
.
No

INSTALL new wheel bearings. For additional inform ation, refer toSection 204
-01
Front Suspension
.
TEST the system
for normal operation.
C

6: CHECK SUSPENSION BUSHES AND BALL JOINTS.
Chec

k all suspension bu
shes and ball joints.
1
Are th
e suspension bushes and ball joints OK?
Yes Vehicle is OK.
No INSTALL new front suspension bushes and ball joints as required. For additional information, refer
toSection 204
-01
Front Suspension
. INSTALL n
ew rear suspension bush
es and ball joints as required.
For additional informat ion, refer toSection 204
-0
2 Rear Suspension
.
P

INPOINT TEST D : THE PEDAL FEELS SPONGY
TE
ST
CONDITIONS
D
ETAILS/RESULTS/ACTIONS
D

1: CHECK FOR SPONGY PEDAL (ENGINE OFF)
Check f

or a firm brake pedal.
1
Is th

e brake pedal effort an
d brake pedal travel normal?
Yes Vehicle is OK.
No GO to D2
.
D2:
CHECK BRAKE PEDAL RESERVE (ENGINE OFF)
Pump th

e brake pedal 10 times and
hold on the final application.
1
Does th
e brake pedal feel fi
rm on final application?
Yes GO to D3
.
No

BLEED the brake system. For additional information, re fer to General Procedures in this section. TEST
the system for normal operation.
D3:
CHECK BRAKE PEDAL RESERVE (ENGINE ON)
Engine is

idle.
1
Apply the brake pedal ligh

tl
y three or four times.
2
W
ait 15 seconds for the vacuum to recover.
3
Push down on

the brake pedal until it stops moving
downward or an increased resistance to the brake
pedal travel occurs.
4
Hol
d the brake pedal in the applied position while increasing the engine speed to 2000 revs/min.
5
Re

lease the accelerator pedal.
6
Does th

e brake pedal move downward as
the engine speed returns to idle?
Yes GO to D4
.
No

CHECK the vacuum to brake booster. For additional information, refer toSection 206
-0
7 Power Brake
Actuation.

D4: CHECK
BRAKE FLUID LEVEL
Check the brake master cyli
nd
er reservoir fluid level.
1
Is the fl
ui
d level OK?
Yes BLEED the brake system. For additional information, re fer to General Procedures in this section. TEST
the system for normal operation.
No CHECK brake master cylinder reservoir sealing points. For additional information, refer to Brake
Master Cylinder in this section. ADD fluid and BL EED the brake system. For additional information,
refer to General Procedures in this section. TEST the system for normal operation. REPEAT road test if
necessary.
P I
NPOINT TEST E : THE
PEDAL GOES DOWN FAST
TES
T
CONDITIONS
D E
TAILS/RESULTS/ACTIONS
E1
:
ROAD TEST VEHICLE
Road test and apply th
e brake peda
l.
1
Is th
e brake pedal ef
fort an
d brake pedal travel normal?
Yes Vehicle is OK.
No GO to E2
.
E2: CHECK BRAK
E FLUID LEVEL
Check the brake master cyli
nd
er reservoir fluid level.
1
Is
t
he fluid level within specification?
Yes GO to E3
.
No
CH
ECK the brake master cylinder reservoir sealing po
ints. For additional information, refer to Brake
Master Cylinder Component Test in this section. ADD fluid and BLEED brake system. For additional
information, refer to General Proc edures in this section. TEST the system for normal operation.
REPEAT road test if necessary.
E3 : CHECK BRAK
E PEDAL TRAVEL-PRESSURIZE SYSTEM
Pump th
e brake pedal rapidly (f
ive times).
1
Does th
e brake pedal trav
el build up and then hold?
Yes BLEED the brake system. For additional information, re fer to General Procedures in this section. TEST
the system for normal oper ation. REPEAT road test.
No GO to E4
.
E4: CHECK FOR
BRAKE SYSTEM LEAKS
Chec
k for e
xternal brake system leaks. For additional information, refer to Master Cylinder in this
section.
1
Are le aks foun
d?
Yes REPAIR as necessary, ADD fluid and BLEED brake syst em. For additional information, refer to General
Procedures in this section. TEST the system for normal operation. REPEAT road test.
No System is OK.
PINPOINT TEST
F : THE PEDAL GOES DOWN SLOWLY
TES
T
CONDITIONS
DE
TAILS/RESULTS/ACTIONS
F1
:
ROAD TEST VEHICLE - CHECK BRAKE PEDAL OPERATION
Chec
k
if the condition occurs duri
ng actual stopping application by applying the brake pedal while
the vehicle is moving.
1
Doe s
the condition occur when the vehicle is moving?
Yes GO to F2
.
No
GO to F
3
.
F2:
CHECK
FOR BRAKE SYSTEM LEAKS
Chec
k for e
xternal brake system leaks. For additional information, refer to Master Cylinder in this
section.
1

Are th
ere any external brake system leaks?
Yes REPAIR as necessary. ADD fluid and BLEED the brak e system. For additional information, refer to
General Procedures in this section. TEST the system for normal operation.
No GO to F3
.
F
3: CARRY OUT A BRAKE MASTER CYLINDER BYPASS TEST
Te

st for brake master cylinder bypass condition. Re
fer to Brake Master Cylinder Component Test in
this section.
1
A
re any concerns found?
Yes INSTALL a new brake master cylinder, ADD flui d and BLEED the brake system. For additional
information, refer to General Proc edures in this section. TEST the system for normal operation.
No System is OK.
PINPO
INT TEST G : EXCESSIVE BRAKE PEDAL EFFORT
TE
ST
CONDITIONS
D
ETAILS/RESULTS/ACTIONS
G1

: CHECK BRAKE PADS
Check the brake pads for wear, contamin

atio
n, correct installation, damage and type.
1
A
re any concerns found?
Yes INSTALL the front brake pads correctly or INSTALL ne w front brake pads if necessary. For additional
information, refer toSection 206
-03
Front Disc Brake
. INSTALL the
rear brake pads correctly or
INSTALL new rear brake pads if necessary. For additional information, refer toSection 206
-04
Rear
Di

sc Brake
. REPEAT road test.
No

GO to G2
.
G2:
CHECK VACUUM
Di

sconnect the vacuum booster hose from the booster.
1
Conne

ct a vacuum/pressure tester to the vacuum hose.
2
Ru

n the engine at normal operating temperature.
3
Re

cord the vacuum reading.
4
Is

the reading 40.5kPa (1
2 in-Hg) or greater?
Yes GO to G3
.
No

LOCATE and REPAIR the source of low vacuum . TEST the system for normal operation.
G3
: INSPECT SYSTEM
Swi

tch the engine off.
1
Re

connect the vacuum hose.
2
Inspect th

e brake booster, rubber grommet, and al
l vacuum plumbing for cracks, holes, damaged
connections, or missing clamps.
3
Pump th
e brake pedal several time
s to exhaust the vacuum. Push down on the brake pedal and hold.
4
Does th
e brake pedal move down
when the engine is started?
Yes Vacuum system is OK.
No GO to G4
.
G4
: CHECK POWER BRAKE BOOSTER VALVE
Check the brake booster valve. For
add
itional information, refer to
Brake Booster in this section.
1
Is th
e power brake booster valve OK?
Yes CHECK the brake booster. Fo r additional information, refer to Brak e Booster in this section. INSTALL a
new brake booster if necessary. TEST the system for normal operation.
No INSTALL a new brake booster valve. TEST the system for normal operation.
P
INPOINT TEST H : BRAKE LOCKUP
DURING LIGHT BRAKE PEDAL FORCE
TE
ST
CONDITIONS
D
ETAILS/RESULTS/ACTIONS
H1

: TEST BRAKE LOCKUP

Road test the veh
icle and a
pply the brake pe dal lightly.
1
Do th
e brakes lockup?
Yes GO to H2
.
No
Vehicle is OK.
H2: INSPECT BRAKE PADS
Inspect brake pads for con
t
amination,
correct installation , damage and type.
1
Ar
e any concerns found?
Yes CHECK the front brake pads. For additi onal information, refer toSection 206
-03 Fr
ont Disc Brake
.
CHECK
the rear brake pads. For additi
onal information, refer toSection 206
-04
Rear Disc Brake
.
INST ALL new brake pads as ne ce
ssary. REPEAT
road test.
No GO to H3
.
H3: INSPECT BRAKE CALI
PERS
Inspect brake cali
pers for bindi
ng, leaking or sticking.
1
A
r
e any concerns found?
Yes CHECK the front brake calipers. For addi tional information, refer toSection 206
-03 Fr
ont Disc Brake
.
CHECK
the rear brake calipers. For addi
tional information, refer toSection 206
-04
Rear Disc Brake
.
IN ST
ALL the brake calipers correctly or INSTALL new
brake calipers as necessary. TEST the system for
normal operation. REPEAT road test if necessary.
No Vehicle is OK.
PI
NPOINT TEST I : BRAKES DRAG
TE
S
T
CONDITIONS
D E
TAILS/RESULTS/ACTIONS
I1
:
ROAD TEST VEHICLE
Ro
ad t
est the vehicle
and apply the brakes.
1
Are the brakes
functioning correctly?
Yes Vehicle is OK.
No GO to I2
.
I2
: CHECK CALIPERS
Check the fr
on
t caliper pistons for binding, leakin
g or sticking. For additional information, refer
toSection 206
-03 Fr
ont Disc Brake
. Check the rear cal
i
per pistons for
binding, leaking or sticking. For
additional information, refer toSection 206
-04
Rear Disc Brake
.
1
Do t
h
e disc brake caliper pistons
and pins bind, leak or stick?
Yes INSPECT the brake calipers and pa rking brake cables. INSTALL new co mponents as necessary. Road
test vehicle.
No GO to I3
.
I3
: CHECK BRAKE BOOSTER
Check the brake booster con
n
ecting rod alignment
and travel. For additional information, refer
toSection 206
-0 7
Power Brake Actuation
. 1
Is the co
nnecti
ng rod OK?
Yes Vehicle is OK.
No INSTALL a new brake booster. For addi tional information, refer toSection 206
-07
Power Brake
Actuation. TEST
the system for
normal operation.
PINPO
I
NT TEST J : EXCESSIVE/ERRATIC BRAKE PEDAL TRAVEL
TE
S
T
CONDITIONS
D E
TAILS/RESULTS/ACTIONS
J
1
: TEST ON ROUGH ROAD
R
oad test the vehi
cle on rough road conditions.
1
Apply the brakes slowly. 2
Is th
e brake pedal ef
fort an
d brake pedal travel normal?

Yes

Vehicle is OK.
No GO to J2
.
J
2: CHECK BRAKE FLUID LEVEL
Check the brake master cyli

nder reservoir fluid level.
1
Is the fl

uid level OK?
Yes GO to J3
.
No

CHECK brake master cylinder reservoir sealing points. For additional information, refer to Brake
Master Cylinder in this section. ADD brake fl uid and BLEED the brake system. For additional
information, refer to General Proc edures in this section. TEST the system for normal operation.
REPEAT road test if necessary.
J
3: CHECK BRAKE PEDAL RESERVE
Engine is

idle.
1
Apply the brake pedal ligh

tl
y three or four times.
2
W
ait 15 seconds for the vacuum to replenish.
3
Push down on

the brake pedal until it stops moving
downward or an increased resistance to the brake
pedal travel occurs.
4
Hol
d the brake pedal in the applied position while increasing the engine speed to 2000 revs/min.
5
Re

lease the accelerator pedal.
6
Does th

e brake pedal move downward as
the engine speed returns to idle?
Yes GO to J4
.
No

CHECK the vacuum to the brake booster. Fo r additional information, refer toSection 206
-0
7 Power
Brake Ac

tuation
.
J

4: CHECK THE FRONT HUB AND BEARING ASSEMBLY
Check the fr

ont hub and bearing assembly. Fo
r additional information, refer toSection 204
-01
Front
Suspe

nsion
. 1
Are th

e front wheel bearings loose?
Yes INSTALL a new front wheel bearin g if damaged. For additional information, refer toSection 204
-01

F

ront Suspension
. TEST
the system for normal operation.
No CHECK the front brake discs for thickness variances. For additional information, refer to General
Procedures in this section.
PINPO
INT TEST K : SLOW OR INCOMPLETE BRAKE PEDAL RETURN
TE
ST
CONDITIONS
D
ETAILS/RESULTS/ACTIONS
K1: C

HECK FOR BRAKE PEDAL RETURN
Ru

n the engine at fast idle while
making several brake applications.
1
Pull the
brake pedal rearward with approximately 44.5 N (10lb) force.
2
Relea

se the brake pedal and measure
the distance to the toe board.
3
Make a hard brake
application.
4
Relea

se the brake pedal and measure the brake
pedal to toe board distance. The brake pedal
should return to its original position.
5
Does th
e brake pedal return
to its original position?
Yes Vehicle is OK.
No GO to K2
.
K
2: CHECK FOR BRAKE PEDAL BINDING
Check the brake pedal to make
s
ure it is operating freely.
1
Is th

e brake pedal operating freely?
Yes INSTALL a new brake booster. For addi tional information, refer toSection 206
-0
7 Power Brake
Actuation. TEST

the system for normal operation.
No REPAIR or INSTALL new brake pedal. TE ST the system for normal operation.

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

cap ven
t holes clogged or air in the hydraulic system.
Brake ped

al effort is excessive. This ma
y be caused by a bind or obstruction in the pedal/linkage, a faulty non return
valve, booster or insuffi cient booster vacuum.
R
ear brakes lock up during light pedal force. This may
be caused by damaged brake pads, an incorrectly adjusted
parking brake, a partially applied parking brake, a damaged ABS sensor or bearing failure.
Brake ped
al effort erratic. This condition could be caused by the brake booste
r or incorrectly installed brake pads.
Brake warning indicator i
s on. This may be caused
by low fluid level or float assembly damaged.
No
n Pressure Leaks
Any reduced fluid v
olume in the brake ma
ster cylinder reservoir condition may be caused by two types of none pressure
external leaks.
Type 1: An external leak may be occur at the master cylinder reservoir cap because of incorre ct positioning of gasket and
cap. Reposition cap and gasket.
Type 2: An external leak may occur at th e reservoir mounting seals. Repair such a leak by installing new seals and make
sure that the reservoir retainin g bolt is correctly installed.

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.