1998 JAGUAR X308 rear suspension

Rear
Suspension - Rear Wheel Bearing
Re
moval and Installation
S

pecial Tool(s)

Hub Holdin

g Tool
204-195 (JD227)

Hub Pu
ller
204-011 (JD 1D)

R
ear-Hub Remover
204-113 (JD 132)

Bearing Cu
p Replacer Adaptor
204-118 (JD 550-4/1)

Bearing Cu
p Replacer Adaptor
204-118 (JD 550-4/2)

D
river Handle
100-013 (18G-134)

Rear-hub spacer
replacer
204-003 (JD 15)
O
il Seal Remover/Replacer

35
.
Tighten hub nut to 304-336Nm.
36. Remove securing nuts and withdraw special tool 204-195
from hub.
37. Install rear wheel. Refer to Section 204-04.
38. Remove stands and lower vehi cle onto wheels. Refer to
section 100-02.
39. Raise vehicle on four-post lift.

40
.
Route parking brake cable through suspension mounting
bracket and secure with clip.

41
.
Route parking brake LH ca ble through equalizer.
42. Install LH cable in connecting clip.

Rear Suspension - Wheel Hub
Seal
Re
moval and Installation
Remov

al
S
pecial Tool(s)

Hub Holdin

g Tool
204-195 (JD227)

Hub Pu
ller
204-011 (JD 1D)

R
ear-Hub Remover
204-113 (JD 132)

O
il Seal Remover/Replacer
205-234 (JD 550-1)
1. CAUTION: 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.
Release parking brake.
2. R
aise the vehicle on a four-post lift.

3. Fully
slacken but do not remove parking brake cable adjuster
nut.
4. Release appropriate side parkin g brake cable from connecting

20
.
Remove nuts and withdraw special tool (204-195) from hub.
21. Install rear wheel. Refer to Section 204-04.
22. Remove stands and lower vehi cle onto wheels. Refer to
section 100-02.
23. Raise vehicle on four-post lift.

24
.
Route parking brake cable through suspension mounting
bracket and secure with clip.

25
.
Route parking brake cable through equalizer (LH side cable
only).

26
.
Install parking brake cabl e in connecting clip.
27. Adjust parking brake cable. Refer to 70.35.10.
28. Lower four-post lift
29. Apply parking brake.
30. Carry out rear wheel alignm ent check and adjust as


necessary. Refer
t
o 204-02 Specification section.

The
Nivomat ride levelling system improves ride quality by al
lowing the use of softer road springs, while controlling the
effects on the suspension of a fully laden vehicle. The system uses special rear dampers in place of the normal units. There
are no other components in th e system. The ride levelling system is comple tely automatic, requiring no input from the
driver.
Ride levelling may be specified as an opti on on certain models; it is not available in north American markets. Ride levelling
and adaptive damping are mu tually exclusive options.
The Nivomat damper:
Su
pplements the load-carrying capacity of th
e road springs at high vehicle loads.
Uses road inputs to the
suspension to power the levelling function.
De

tects suspension height dire
ctly from road wheel travel.
Provi
des load-dependent spring rates; the ac
cumulator gas pressure increases with load.
Pr
ovides load-dependent damping; the fluid pressure increases with load.
Op

eration
F
ollowing an increase in vehicle loading,
the dampers adapt to maintain the height of the vehicle within its design range.
The system uses road inputs to the suspension to power the levelling action, and requires up to approximately two
kilometers of travel, following a change in load, to complete the process.
Normal movement of the suspension caus es a pumping action to occur within the damper, as a result of extension and
compression of the pump rod in the pump chamber. Hydraulic fluid is pumped from the pump cham ber into a high pressure
gas accumulator. The increase in gas pressure augments the force developed between th e vehicle axle and the body,
thereby providing lift.
It
em
De
scription
1Pi

ston rod
2Pum

p chamber
3High

pressure
gas accumulator
4Diaphragm
5Co
ntrol orifice
6Pump rod
7Low pressure gas ch

amber
8Low pressure oil

reservoir


Ride Levelling

Is hard-wi
red to the instrume
nt cluster message center.
Is hard
-wired to the J1962 diagnostic connector.
Op
era
tion
Th
e
system selects the soft or
firm damper setting according to the current ro ad and driving conditions, to optimise vehicle
ride and handling.
With the vehicle stationary, the dampers are in the firm setting, but will normally switch to the soft setting when the vehicle
exceeds 8 km/h (5 mile/h); all dampers are switched simultaneously.
Sudden movement of the vehicle body, in response to road inputs, is detected by the vertical accelerometers, and the ADCM
switches the dampers to the firm setting to give improved damping of the resultant oscillations.
When cornering forces are detected by th e lateral accelerometer, the ADCM switches the dampers to the firm setting to
reduce the roll rate an d improve wheel control.
After the event has passed, the dampers revert to the soft setting.
When the footbrake is applied, the ADCM re ceives a signal and calculates the rate of vehicle deceleration. If the deceleration
rate is greater than a certain threshold, the dampers are switched to the firm setting to reduce the pitch rate and improve
wheel control.
If a system failure occurs, the ADCM grounds the output line to the instrument cluster message center, which displays a
text warning SUSPENSION FAULT and illuminates the amber warning lamp. Under fault conditions the system always fails to
the firm setting, so that the vehicle will be safe to drive un der all road and driving conditions.
Connector Pin Identity Chart for EM068

Pin
Number
Ci
rcui
t
Circuit Functi
on
1System erro
r output to instrument
cluster
2Not
used
3O/
P a
ccelerometer ground
4 to

9
Not
used
10K-
li
ne to diagnostic socket
11Ignition su
pply +12V
12Not
used
13Control signal (+ve) output
to l
eft-hand rear damper
14Control signal (+ve) output
to right-hand front damp
er
15Control signal (+ve) output
to right-hand rear
damper
16
a
nd 17
No
t
used
18Ground
19No
t
used
20Lateral
accelerometer i
nput
21Front vertical ac
celerometer in
put
22Rear vertical
acce
lerometer input
23No
t
used
24R
o
ad speed input from
instrument cluster
25Power output +5V to suppl y accelerometers
26Brake peda
l input

Brake System - General Inform
ation - Brake System
D
iagnosis and Testing
Principles of Operations
The brake system operates by transferring effort applied to th e brake pedal, by the driver to the brakes at each wheel.
The braking effort is distributed to each wheel, using a hydraulic system. The system is assisted using a vacuum brake
booster that reduces pedal effort for a given hydraulic pressure. The parking brake operates on the rear wheels and is
applied using a hand operated control.
I
nspection and Verification
•
NOTE: Prior to carrying out any diagno
sis, make sure that the brake system warning indicator is functional.
Visually examine the front and rear tire and wheel assemblies for damage such as un even wear patterns, tread worn out or
sidewall damage. Verify the tires are th e same size, type and, where possible, same manufacture. Replace the damaged
wheel or excessively worn tire. For a dditional information, refer toSection 204
-0
4 Wheels and Tires
.
W
heels and tires must be cleared of an
y foreign matter and tire pressures ad justed to the correct specification.
If the tires exhibit uneven wear or feathering, the cause must be corrected. Check the steering and suspension components
for damage or wear and, if ne cessary, check and adjust front wheel alignment. For additional information, refer toSection
204
-00 Suspen
sion System
- General Informati
on
.
Road Test


V
isual Inspection Chart
Carr

y out a road test to compare actual vehicle braking performance with the
performance standards expected by the
driver. The ability of the test driver to make valid compar isons and detect performance deficiencies will depend on
experience.
The driver should have a thorough knowledge of brake system operation and accepted general performance guidelines to
make good comparisons and de tect performance concerns.
An experienced brake technician will always establish a route that will be used for all br ake diagnosis road tests. The roads
selected will be reasonably smooth and level. Gravel or bump y roads are not suitable because the surface does not allow the
tires to grip the road equally. Crowned roads should be avoide d because of the large amount of weight shifted to the low set
of wheels on this type of road. Once th e route is established and consistently used, the road surface variable can be
eliminated from the test results.
Before a road test, obtain a complete description of the customer concerns or suspec ted condition. From the description, the
technician's experience will allow the te chnician to match possible causes with symptoms. Certain components will be
tagged as possible suspects while others wi ll be eliminated by the evidence. More importantly, the customer description can
reveal unsafe conditions which should be ch ecked or corrected before the road test. The description will also help form the
basic approach to the road test by narrowing the concern to specific components, vehicle speed or conditions.
Begin the road test with a general brake performance check. Keeping the description of the concern in mind, test the brakes
at different vehicle speeds using both ligh t and heavy pedal pressure. To determine if the concern is in the front or rear
braking system, use the brake pe dal and then use the parking brake control. If the condition (pull, vibration, pulsation)
MechanicalElectrical
Brake m
aster cylinder
Parkin
g brake switch
Brake ca

liper piston(s)
D
amaged or corroded wiring harness
Brake di

scs
B
rake master cylinder fluid level switch
Wh

eel bearin
gs
Brake pads
Power brake booster
Brake ped

al linkage
Boost

er vacuum hose
Tire

s
De

bris

oc
curs only with the parking brake, th
e concern is in the rear brake system.
If the concern becomes evident during this check, verify it fits the description given before the road test. If the concern is
not evident, attempt to duplicate the condition using the information from the description.
If a concern exists, use the Symptom Chart in order to isolate it to a specific sub-system and condition description. From
this description, a list of possible sources can be used to further narrow the cause to a specific component or condition.
Sym
ptom Chart
Sy
m
ptom
Possib
l
e Sources
Acti
o
n
Brakes
n
oisy
Brake pads.
Brake di
scs
.
*
*
GO to Pinpoint
Tes
t A.
*
Vibration wh
en brakes
are applied
Wh eels require bala
ncing.
Wheel hub nuts.
Caliper mounting bolts.
Brake pads.
Foreign material/scr atches/corrosion
on brake disc contact surfaces. Excessive brake disc thickness
variation. Excessive brake disc runout.
Wheel bearing wear or failure.
Suspension bush wear or failure.
Steering bush wear or failure.
*
*
*
*
*
*
*
*
*
*
Go to Pinpoint
Tes
t B.
*
The brakes pull or drif tTire pressures/wear.
Calipers.
Brake pads.
Brake di
scs.
Wheel alignment adjustment.
Wheel bearing.
Suspension bushes and ball joints.
*
*
*
*
*
*
*
GO to Pinpoint
Tes
t C.
*
The pedal feels spongyAir i
n brake system.
Leak in hydraulic system.
Brake booster/master cylinder.
Brake pads.
*
*
*
*
GO to Pinpoint Tes
t D.
*
The pedal goes down
fa s
t
Ai
r i
n brake system.
Leak in hydraulic system.
Brake booster/master cylinder.
Brake pads.
*
*
*
*
GO to Pinpoint
Tes
t E.
*
The pedal goes down
slowl yAir i
n brake system.
Brake booster/master cylinder.
*
*
Go to Pinpoint
Tes
t F.
*
Excessive brake pedal
effor tBrake pads.
Brake booster.
*
*GO to Pinpoint
Tes
t G.
*
Brake lockup du ring ligh
t

brake pedal force
Brake pads.
Calipers.
*
*GO to Pinpoint
Tes
t H.
*
Brakes d r
ag
Parkin
g brake con
trol
applied/malfunction. Seized parking brake cables.
Seized caliper slide pins.
Seized caliper.
Brake booster.
Pedal gear.
*
*
*
*
*
*
GO to Pinpoint
Tes
t I.
*
Exce ssi
ve/Erratic brake
pedal travel
Hydrau li
c system.
Brake pads.
Brake discs.
Hub and bearing assembly.
*
*
*
*
GO to Pinpoint
Tes
t J.
*
The red brak e warning
indi
cator is always on
Fl
ui
d level.
*
F I
LL the system to specification. CHECK for leaks.
*
Brake flu i
d level sensor.
*
I N
STALL a new brake master cylinder fluid
reservoir. For additional in formation, refer toSection
206
-0 6
Hydraulic Brake Actuation
.
*
Parkin
g brake con
trol.
*
REL
E
ASE and ADJUST the parking brake. For
additional information, refer toSection 206
-05
Parkin g Brake an
d Actuation
.
*
E
l
ectrical circuit.
*
F or additional
information, refer to PDU for
analysis/rectification of the concern.
*
Sl
ow or i
ncomplete brake

Brake peda
l binding.
*
GO to Pinpoint Tes
t K.
*

pedal retu rnBr
ake booster/master cylinder.
*