1998 JAGUAR X308 Connector

The
measurement of the maximum system pressure, (which is
governed by the pressure relief valve) is achieved by
inserting the Service Tool (pressure gauge and adaptors) into th e fluid circuit of the power steering system. Run the engine
at idle speed, turn the st eering from lock to lock and read the ma ximum pressure recorded on the gauge.
Installin
g Test Equipment
To
in
stall the pressure test equipment:
Pla
c
e a suitable drain tray be
low the power steering pump.
Install a hose clamp on
the re
servoir to pump hose prior to disconnecting any hoses, to avoid unnecessary loss of
fluid.
Disc
onnect the hose from the power st
eering pump high pressure outlet.
Install the pu
mp outlet to hose adaptor (5
). Do not omit the 'O' ring seal (9).
Connect the power steering
pump
adaptor to control valve hose (6) of the test equipment.
Install th e adaptor (4) in th
e high
pressure hose previously removed from the power steering pump outlet.
Conn
ect the connector (3) of the test equipment hose (2) to the adaptor (4).
R
e
move the hose clamp fro
m the reservoir hose.
Start th
e engine.
With the control valve (7) OPEN and the engine idli ng, the following system pressures may be checked:
Du
ring turning.
W
h
en the steering is
held on full lock.
With
the steeri
ng at rest.
• CAUTIONS:
To avoid excessive heating of the po wer steering pump, do not close the valve for longer than 5 seconds maximum.
Do not drive the vehicle with the test equipment installed.
With the control valve (7) CLOSED the power steering pump maximum ou tput pressure can be checked.
Removing Test Equipment
To
remove the test equipment:
Install a hose clamp
on
the reservoir to power steering pump hose.
Re
movi
ng the test equipmen
t is a reversal of the in stallation instructions.
Install a new '
O
' ring seal (9) to the power steering pump high pressu
re outlet to hose connection.
Instal
l the original hose to
the power steering pump.
Re
move the clamp from the reservoir to
the power steering pump hose.
Top-up the reservoir flui
d.
Ble
e
d the power steerin
g system. For additional information,
REFER to Power Steering System Bleeding
- in thi
s section.
Stee
ring Fault Diagnosis by Sympt
om Charts
Leakage
52
11-0
11-03/1
Pump High Pressure Ou
tlet
to Hose Adaptor
621
1
-011-02
Pump Adaptor
to Contro
l Valve Hose
721
1
-011-01
Control Valve
82
11-
011
Pressure Gauge
9-'O
'
Ring Seal
Cond
iti
on
Possib
l
e Sources
Acti
o
n
Co
nfirm
the position of the fluid
leak.
CLEAN th
e area of the leak.
In
s
pect the area and confirm the exact position of leak.
Make sure the fluid
is not from anoth
er system on
the vehicle.

Hiss (Swish)
Hiss or Val
ve Hiss is a high-frequency so
und coming from the steering gear when the system is loaded. It is a rushing or
"swish" noise that doesn't change frequency with RPM. Hiss is the general noise generated by the flow of hydraulic fluid
through restrictions in the steer ing system. Restrictions include the rotary stee ring valve, power steering tubes, connectors,
tuning orifices, etc. Hiss can be air- borne and structure-borne, but the structure-borne path through the steering
intermediate shaft is usually dominant.
Moan (Groan)
Moan is the general structu r
e-borne noise of the steering system. Moan is primarily transmitted to the driver via the body
structure through the pump mount, engine mounts, power steering lines and power steering brackets. On some vehicles,
moan is a load humming noise, often present when the wheel is turned and the system is loaded. It may change frequency
with engine RPM and if the sy stem is loaded or unloaded.
Rack Knock (R
ack Slap)
CAU
T
ION: DO NOT attempt to adjust the stee
ring gear yoke. Failure to follow this instruction will result in the steering
gear warranty to become invalid.
Rack Knock is a rattle sound an d steering wheel vibration caused by separation of the steering gear and pinion while driving
over bumps. It is a structure-borne noise transmitted throug h the intermediate shaft and column. Rack knock can also be
heard as a "thump" or impact noise that occurs with the vehicle stationary when the steering wheel is released from a
loaded position and allowed to return to rest . Noise occurs with the engine on or off.
Rattles
Ra
ttles are noises caused by knocking or hitting with components in the steering system. Steering rattles can occur in the
engine compartment, the suspension, or the passenger compartment . Rattles can be caused by loose parts, movable and
flexible parts, and improper clearances.
Squea k
s/Scrapes
Squeaks/Scrapes are noises due
to fri
ction or component rubbi
ng anywhere in the steering system. Squeaks/Scrapes have
appeared in steering linkages and jo ints, in column components and in co lumn and steering wheel trim parts.
Weep
We
ep is an air-borne noise, occasionally
generated when turning the steering across lock at a constant rate. When present
on a vehicle the noise, once initiated can often be maintained across a large proportion of the available steering movement.
Whistle
Wh
istle is similar to hiss but is louder and of a higher frequency. It is also more
of a pure tone noise than hiss. Whistle is
air-borne and is generated by a high flow rate of hydraulic fluid through a small restriction.
Zip

Zip n
o
ise is the air-borne noise
generated by power steerin g pump cavitation when power steering fluid does not flow freely
through the suction hose from the rese rvoir to the pump. Zip primarily occurs during cold weather at start-up.
Steering System Vibrations and Harshne
ss
Buzz
Buzz is a tactile rotary vi

bration felt in
the steering wheel for slow steering inputs. Buzz can also be called a grinding feel
and it is closely related to grunt and is caused by high system gain with low damping. Buzz is generally excited during
parking manoeuvres with low to medium speed steering input.

Power Steering - Power Steering
Description an
d Operation

Parts List
The power steering system is a rack and pinion design, with an engine-dri ve n pump providing the steering assistance. The
system features variable steering assistance with vehicle spee d, a variable ratio steering rack, and a hydraulic control valve
which has a torsion bar arrangement giving improved center feel to the steering.
Absolute cleanliness must be observed wh en replenishing the fluid or dismantling any part of the system. If any major
component is renewed a new fluid rese rvoir must be fitted. New fluid from a sealed container must be used.
It
em
Par
t Number
De
scription
1—Steeri

ng rack assembly
2—Power as

sisted steering pump
3—F

luid reservoir
4—F

luid cooler
5—Hoses and pipework
6—In-

line quick-fit connector

P a
rts List
The supply and return pipes are secured to the hydraulic control valve housing by a latch-plate having a single fixing screw.
The latch-plate is captive to the supply pipe. Each pipe has an O-ri ng which is a serviceable item.
In-Line Quick-Fit Connector

Parts List

Ite
m
Par
t
Number
De
scr
iption
1—Return
pipe (RH drive)
2—Supply pipe (RH
drive)
3—Latc
h-plate
4—Latch-
plate securing screw
It
e
m
Par
t
Number
De
scr
iption
1—Qu
ic
k-fit connector
2—Return
pipe

Latch
-Plate Location

m
ember. The quick-fit connector O-rings are not serviceable.
Special tool JD 182 is required to disconnect the quick-fit connector.
Hydraulic System


P
arts List
Hydraulic System

Op
erating Principle
The rot
ary motion of the steering wheel is converted, via the st
eering rack pinion, to the lateral motion of the rack. Steering
assistance is provided by pressurized fluid being directed against a piston operating within the rack cylinder. Rack
movement is achieved by diffe rential pressures being applied on either si de of the rack piston, caused by unequal
restrictions within the hydraulic control valve.
The main components of the hydraulic control valve are the rota ry distributor, control sleeve and hydraulic reaction piston.
It
em
Par
t Number
De
scription
1—F

luid reservoir
2—Pum

p
3—Pressure and fl

ow limiting valve
4—Supply line
5—R

eturn line
6—Steeri

ng rack
7—Pin

ion
8—O

perating cylinder and piston
9—Hydrau

lic control valve
10—Hydraulic reaction

piston
11—Control

sleeve
12—R

otary distributor
13—F

luid cooler


A
quick-fit connector with double O-ring se
als is incorporated in the return line and is clipped to the right-hand chassis side

Power Steering - Power Steering
Diagn
osis and Testing
Refer to the Description and Operation sub-section for details of the power operated steering system and Servotronic control
system.
Power Steer ing Pressure Test

Test Equ
i
pment

Parts List
In
stalling Test Equipment
To
in
stall the pressure test equipment:
Pla
c
e a suitable drain tray below the PAS pump.
Install a hose clamp
on
the re
servoir to pump hose prior to disconnecting any hoses, to avoid unnecessary loss of
fluid.
Di sc
onnect the hose from the PAS pump high pres
sure outlet.
Ins
tall the pump outlet to hose ad
aptor. Do not omit the O-ring.
Conn
ect the pump adaptor to control valve hose of the test equipment.
Install th
e adaptor in the high pressure hose previ
ously re
moved from the pump outlet.
Conne
ct the connector of the test equipment hose to the adaptor.
R
e
move the hose clamp fro
m the reservoir hose.
Start th
e engine.
With the control valve OPEN and the engine idling , the following system pressures may be checked:
Du
ring turning.
W
h
en the steering is
held on full lock.
With
the steeri
ng at rest.
• WARNINGS:
TO AVOID EXCESSIVE HEATING OF THE PAS PUMP, DO NOT CLOSE THE VALVE FOR LONGER THAN NECESSARY.
Ite
m
Par
t
Number
De
scr
iption
1—Pressure

gauge hose
2—Pump return hose
3—Pump return hose connector
4—Test equi
pment to
HP hose adaptor
5—Pump HP outlet to hose adaptor
6—Pump adaptor
to control valve hose
7—Control valve

Righ
t-hand drive vehicles
All vehicles

7. De
tach the steering
column lower shaft.
1. Loosen the steering column lower shaft retaining bolt.
2. Remove and discard the st eering column lower shaft
retaining bolt.
3. Detach the steering column lower shaft.

8. Di
sconnect the steering gear transducer electrical connector.

9. Cut an
d discard the stee
ring gear transducer harness tie-strap.

10
.
Cut and discard the power steeri ng return pipe tie-strap.
11. Detach the power steering re turn pipe from the mounting
rubber.

In
stallation
All vehicles

Route t
he steering gear transducer harness from behind
the power steering return pipe (right-hand drive vehicles
only).

12 . Remove the
power steering supply and return pipe retaining
plate bolt and with draw the plate.

13 . D
rain the power steering fluid.
Di
sc
onnect the power steering
supply and return pipes and
allow the fluid to drain.
Remove an d discard the ´O´ring seals from the
pipe
connectors.
Fi t su
itable blanking caps
to the pipe connectors and
pinion housing ports.
14. Remove the drain pan and discard the fluid.
15. NOTE: The steering gear mounting bushings are handed;
they are marked accordingly and must be replaced as a pair.
Remove the steering gear mo unting bracket bushings.
For additional information, refer to: Steering Gear Bushing

( 21
1-02 Power Steering, Removal and Installation).
16. NOTE: When removing the steering gear, manoeuvre the
power steering return pipe past the pinion housing to steering
gear pipes.
Remove the steering gear.
17. Using a tap (M10 x 1.5 mm), clean the steering gear to
crossbeam bolt hole threads.
1. If a new steering gear assembly is to be fitted, make sure
steering gear is centrali zed before installation.