10.2 SERVICE
PROCEDURES - SAFETY RELATED
10.2.1
Airbag
The electrically activated driver's side airbag is attached to the steering wheel hub and is fed by two wires from the
column stalk assembly. Electrical input to the column stalk assembly for the airbag is provided by a dedicated harness
which is encased in a yellow sleeve. A mechanism in the stalk assembly called the 'cable reel cassette' provides conti
-
nuity from the static column to the steering wheel. The 'cable reel cassette' is driven by a tang which locates in the
steering wheel. Because the connection is by wires, and the cassette assembly is only capable of approximately five
(5) full turns,
it is critically important that initial positioning is correct, see Section 15. It is equally important that fitting of the steering wheel, connection of the column, lower shaft and steering rackshould
ONLY be made with the steering rack in the center of its travel.
WARNING: DO NOT REMOVE THE STEERING COLUMN FROM THE VEHICLE WITH THE STEERING WHEEL AT- TACHED UNLESS THE STEERING IS CENTERED AND THE COLUMN LOCK IS ENGAGED. IF THE LOCK
BARREL
IS TO BE RENEWED, 'LOCK-WIRE THE ASSEMBLY TO PREVENT ROTATION. FAILURE TO OB- SERVE THIS AND CONSEQUENT DAMAGE TO THE 'CABLE REEL CASSETTE MAY RESULT IN AN INOP- ERATIVE AIRBAG SYSTEM. SEE LABEL ON STEERING WHEEL HUB.
10.3 SERVICE PROCEDURES
10.3.1 Working Practices
It is not recommended that either the steering rack or engine driven pump assemblies are repaired in any way other
than in accordance with the repair procedures described in this manual. The fluid reservoir and filter is a disposable
assembly and no attempt should be made to clean it internally. Genuine replacement units must be fitted following
routine service or diagnostic confirmation of the failure of any component.
The importance of cleanliness cannot be over
-stressed, not only with new parts but also those which may havefailed.
In-service contamination of the hydraulic system is a major cause of failures and may be avoided with good working
practices and care. All new units and pipes must be supplied with suitable blanks in every orifice. Should a unit not
have blanks fitted, do not use
it - return it to the supplier with an appropriate reason for your action.
To help the manufacturer diagnose problems and avoid post-removal contamination; provide full details of the fault
and plug all connections as soon as they are released. All suspect units must be returned to Jaguar Cars complete
with relevant documentation.
CAUTION: It is imperative that the power steering system does not become contaminated in any way. Always de- cant fluid from afresh sealed container and clean the area around the reservoir neck both before and after topping-up. Never return drained fluid to the system.
10.3.2
Position the vehicle on a level surface with the engine sta- tionary and fluid cold. Add fluid, if required, so that the level
falls BETWEEN the marks
Fig.1.
10.3.3 System Bleed (following maintenance)
To avoid fluid aeration and possible pump damage, the in- itial fill process must be carried out with the ignition OFF.
Set the fluid level approximately 20 mm above the upper
dipstick level, and cycle the steering no less than three (3) times from lock to lock (this may be best achieved with the
front wheels off the ground). As air is expelled thefluid level
will fall, the level should be corrected. Start the engine and
further cycle thesteering until the fluid level becomes stable.
Stop the engine and finally set the level in accordance
with the fluid level check procedure.
10.3.4 Fluid Reservoir
The reservoir has an integral, non-serviceable, return-side
filter. Should any component be renewed or the system
'broken into' for any reason,
it is essential that the reservoir and the fluid are changed. Under normal operating condi- tions it is not necessary to change the fluid.
10.3.5 Hydraulic Connections
Fluid
Level Check and
Top-up
Jf7-281
Fig. 1
All hydraulic connections and surrounding areas should be scrupulously cleaned before and after work. Please note
that the steering rack valve block connections for FEED and RETURN are common in size. Ensure that the pipes are
correctly fitted, the uppermost one being the high pressure FEEDfrom the steering pump and the lower (RETURN) hav- ing a double depth hexagon tube nut.
X300 VSM 5 issue 1 August 1994
Pressure conscious reduction valves (PCRVs) are fitted between the outlet of the valve block and the rear brake circuit
to optimize. The valves are fitted to prevent over braking due to the increased size of the rear brake calipers which are
required for traction control. Up to a threshold of 15 bar, brake pressure to the front and rear brakes is equal. Above
15 bar the PCRVs reduce pressure to the rear brakes to provide a closer balance between front and rear brakes and
optimize road adhesion.
Wheel speed sensors are fitted to all wheels to transmit wheel speed information to the control module. The module
uses this information to modulate brake pressure during anti
-lock braking or traction control.
12.1.3. Anti-lock Braking Operation
170 287
1. Vacuum booster 9. Pressure conscious reduction valve
2. Vacuum hose 10. Ventilated brake rotor
3. Tandem master cylinder 11. Single piston caliper
4. Primary brake circuit 12.
%way brake pipe connector
5. Secondary brake circuit 13. Wheel speed sensor
6. Hydraulic pump I motor unit 14. ABS warning lamp 7. Valve block 15. Brake fluid level warning lamp
8. ABSICM
Fig. 1 Brake System (non-Traction Control)
The rear brakes (see Fig. 1) are controlled collectively on a
'select-low' principle. Under ABS braking conditions, equal
brake pressure is applied to both rear calipers, although only one wheel may have a tendency to lock.
The valve block has three outlet
ports, Brake fluid volume is supplied equally to the rear brakes via the %way brake
pipe connector.
Issue 1 August 1994 4 X300 VSM
13.4 TRUNK
13.4.1 Trunk, Description
The trunk houses the spare wheel, the battery, an electrical carrier containing electrical fuses, relays and modules and
a compact disc auto-changer attached to body bracketry. The trunk is fitted with push-fit, velour finish, liners (1 Fig. 1) to the sides and front inner panel; the trunk floor is covered with carpet attached to a removable floor board (2 Fig. 1) and a battery cover (3 Fig. I), one covering the spare wheel and wheel changing equipment, the other covering the
battery and electrical carrier.
The floor board rests on the spare wheel, the front and rear edges
of the floor board locating in blocks on the fuel tank
backboard and on the rear of the body. The blocks accommodate the two possible height settings caused by the differ- ence in thickness between the space saver and full sized spare wheels.
A tread plate (4 Fig. 1) is attached to the trunk sill and a liner is fitted to the rear of the trunk below the sill. Interior trim finisher panels are fitted to the rear lamp units accessed from the trunk opening.
The trunk lid
(5 Fig. 1) is fitted with a removable moulded liner and two trunk illumination lights; the lid is supported by two gas struts, attached through press-on fittings between the inner wheel arch and trunk hinge (6 Fig. 1). A warning
triangle is attached by a bracket to the trunk lid and retained in the open position by a rubber block (Europe inc UK only).
Trunk locking is based on a central latch and striker, operated electrically through the central locking system
by an ad- jacent actuator or by key in a barrel lock located behind the trunk lid badge.
For details on renewal
of trunk front and side liners, trunk carpet, trunk seal retainer and battery cover, see relevant
Service Repair Operations.
2 4 3 J76-1056
1. Trunk Liners 2. Removable floor board 3. Battery cover
4. Treadplate 5. Trunk lid 6. Hinge
Fig.
1 Trunk Components and Trim
Issue 1 August 1994 X300 VSM 38
Tire Replacement And Wheel hterchanging
WARNING: UNDER NO CIRCUMSTANCES SHOULD CROSS-PLY TIRES BE FITTED.
When renewal of tires is necessary, it is preferable to fit a complete set.
Should eitherfront or reartires only (i.e.
notthe full set) show a necessityfor renewal, newtires must befitted to replace
the worn ones.
No attempt must be made to interchange tires from the front to the rear orvice-versa, as wear produces a characteristic
pattern on each tire depending upon its position on the vehicle. If this position is changed after wear has occurred, the
performance of the tire will be adversely affected.
It should be remembered that new tires must be balanced.
The radial ply tires specified here are designed to meet the high speed performance of this vehicle. Only tires of ident
- ical specification as shown in this section must be fitted as replacements. If two replacement tires are fitted to one axle,
they must be of the same type and pattern as those on the other axle, i.e. tires must be used in sets of four of the same
manufacturer and tread pattern,
not intermixed.
Tire Fitments
32 Liter 4.0 Liier 4.0 Liter SC 6.0 Liter 6.0 Liter 0
(Normally (Daimler & (UK, Euro, ROW
Aspirated) Federal
XJ12) XJ12)
Standard 225 160 ZR16 225 I60 ZR16 - 225 I60 ZR16
225
1 55 ZR16 225 I55 ZR16 - - 225 I55
ZR16
- 255 I45 ZR17 - -
Space saver 115/85R18 115/85R18 115185 115185 115185
(where fitted) RI8 R18 RI8
Recommended tires
The following tires are recommended:
225 I60 ZR 16 ...................................................... Pirelli P4000 E
225 155 ZR 16 ...................................................... Pirelli P6000
225 155 ZR 16 ...................................................... Dunlop SP Sport 2000
255
145 ZR 17 ...................................................... Pirelli P Zero
115185 R 18 Pirelli .......................................................
0
Recommended Winter (Snow) Tires
Tire designation:
225 I60 R 16 ...................................................... Goodyear Eagle GW M+S
225 155 R 16 ....................................................... Pirelli Winter 210 M+S
225 I55 R 16 ...................................................... Michelin 330 M+S
Only use winter tires in complete sets of the same type I size.
CAUTION: Tire directional indicators must rotate in a clockwise direction when viewed from the right-hand side of
the vehicle, and in an anti-clockwise direction when viewed from the left-hand side.
The recommended pressures for winter tires are shown in the table of inflation pressures on the following page.
0
X300 VSM Issue 1 August 1994 AI-95MY 10