1997 JAGUAR XJ6 inflation pressure

3261 Jaguar XJ6
0•14Weekly checks
Tyre condition and pressure
It is very important that tyres are in good
condition, and at the correct pressure - having
a tyre failure at any speed is highly dangerous.
Tyre wear is influenced by driving style - harsh
braking and acceleration, or fast cornering,
will all produce more rapid tyre wear. As a
general rule, the front tyres wear out faster
than the rears. Interchanging the tyres from
front to rear ("rotating" the tyres) may result in
more even wear. However, if this is
completely effective, you may have the
expense of replacing all four tyres at once!
Remove any nails or stones embedded in the
tread before they penetrate the tyre to cause
deflation. If removal of a nail does reveal thatthe tyre has been punctured, refit the nail so
that its point of penetration is marked. Then
immediately change the wheel, and have the
tyre repaired by a tyre dealer.
Regularly check the tyres for damage in the
form of cuts or bulges, especially in the
sidewalls. Periodically remove the wheels,
and clean any dirt or mud from the inside and
outside surfaces. Examine the wheel rims for
signs of rusting, corrosion or other damage.
Light alloy wheels are easily damaged by
"kerbing" whilst parking; steel wheels may
also become dented or buckled. A new wheel
is very often the only way to overcome severe
damage.New tyres should be balanced when they are
fitted, but it may become necessary to re-
balance them as they wear, or if the balance
weights fitted to the wheel rim should fall off.
Unbalanced tyres will wear more quickly, as
will the steering and suspension components.
Wheel imbalance is normally signified by
vibration, particularly at a certain speed
(typically around 50 mph). If this vibration is
felt only through the steering, then it is likely
that just the front wheels need balancing. If,
however, the vibration is felt through the
whole car, the rear wheels could be out of
balance. Wheel balancing should be carried
out by a tyre dealer or garage.
Tread Depth - visual check
The original tyres have tread wear safety
bands (B), which will appear when the tread
depth reaches approximately 1.6 mm. The
band positions are indicated by a triangular
mark on the tyre sidewall (A).1Tread Depth - manual check
Alternatively, tread wear can be
monitored with a simple, inexpensive device
known as a tread depth indicator gauge.2Tyre Pressure Check
Check the tyre pressures regularly with
the tyres cold. Do not adjust the tyre
pressures immediately after the vehicle has
been used, or an inaccurate setting will result.3
Tyre tread wear patterns
Shoulder Wear
Underinflation (wear on both sides)
Under-inflation will cause overheating of the
tyre, because the tyre will flex too much, and
the tread will not sit correctly on the road
surface. This will cause a loss of grip and
excessive wear, not to mention the danger of
sudden tyre failure due to heat build-up.
Check and adjust pressures
Incorrect wheel camber (wear on one side)
Repair or renew suspension parts
Hard cornering
Reduce speed!
Centre Wear
Overinflation
Over-inflation will cause rapid wear of the
centre part of the tyre tread, coupled with
reduced grip, harsher ride, and the danger of
shock damage occurring in the tyre casing.
Check and adjust pressures
If you sometimes have to inflate your car’s
tyres to the higher pressures specified for
maximum load or sustained high speed, don’t
forget to reduce the pressures to normal
afterwards.
Uneven Wear
Front tyres may wear unevenly as a result of
wheel misalignment. Most tyre dealers and
garages can check and adjust the wheel
alignment (or "tracking") for a modest charge.
Incorrect camber or castor
Repair or renew suspension parts
Malfunctioning suspension
Repair or renew suspension parts
Unbalanced wheel
Balance tyres
Incorrect toe setting
Adjust front wheel alignment
Note: The feathered edge of the tread which
typifies toe wear is best checked by feel.

3261 Jaguar XJ6
REF•16Fault finding
6 Suspension and steering systems
5 Braking system (continued)
Brake pedal feels spongy when depressed
m mAir in hydraulic lines (Chapter 9).
m mMaster cylinder mounting bolts loose (Chapter 9).
m mMaster cylinder defective (Chapter 9).
Brake pedal travels to the floor - no resistance
m
mLittle or no fluid in the master cylinder reservoir caused by leaking
caliper piston(s), damaged or disconnected brake lines (Chapter 9).
Handbrake does not hold
m mHandbrake cable or handbrake shoes improperly adjusted
(Chapter 9).
m mHandbrake shoes need replacement (Chapter 9).
Note:Before attempting to diagnose the suspension and steering
systems, perform the following preliminary checks:
a) Tyres for wrong pressure and uneven wear.
b) Steering universal joints from the column to the steering gear for
loose connectors or wear.
c) Front and rear suspension and the rack and pinion assembly for
loose or damaged parts.
d) Out-of-round or out-of-balance tyres, bent rims and loose and/or
rough wheel bearings.
Vehicle pulls to one side
m mMismatched or uneven tyres (Chapter 10).
m mBroken or sagging springs (Chapter 10).
m mWheel alignment out of specifications (Chapter 10).
m mFront brakes dragging (Chapter 9).
Abnormal or excessive tyre wear
m
mWheel alignment out of specifications (Chapter 10).
m mSagging or broken springs (Chapter 10).
m mTyre out-of-balance (Chapter 10).
m mWorn shock absorber (Chapter 10).
m mOverloaded vehicle.
m mTyres not rotated regularly.
Wheel makes a “thumping” noise
m
mBlister or bump on tyre (Chapter 10).
m mImproper shock absorber action (Chapter 10).
Shimmy, shake or vibration
m
mTyre or wheel out-of-balance or out-of-round (Chapter 10).
m mLoose, worn or out-of-adjustment wheel bearings (Chapter 1).
m mWorn tie-rod ends (Chapter 10).
m mWorn balljoints (Chapter 10).
m mExcessive wheel runout (Chapter 10).
m mBlister or bump on tyre (Chapter 10).
Hard steering
m
mLack of lubrication at balljoints, tie-rod ends and rack-and-pinion
assembly (Chapter 1).
m mFront wheel alignment (Chapter 10).
m mLow tyre pressure(s) (Chapter 1).
Poor returnability of steering to centre
m
mLack of lubrication at balljoints and tie-rod ends (Chapter 1).
m mBinding in balljoints (Chapter 10).
m mBinding in steering column (Chapter 10).
m mLack of lubricant in rack-and-pinion assembly (Chapter 10).
m mFront wheel alignment (Chapter 10).
Abnormal noise at the front end
m
mLack of lubrication at balljoints and tie-rod ends (Chapter 1).
m mDamaged shock absorber mounting (Chapter 10).m mWorn control arm bushings or tie-rod ends (Chapter 10).
m mLoose stabiliser bar (Chapter 10).
m mLoose wheel nuts (Chapter).
m mLoose suspension bolts (Chapter 10).
Wander or poor steering stability
m
mMismatched or uneven tyres (Chapter 10).
m mLack of lubrication at balljoints and tie-rod ends (Chapter 1).
m mWorn shock absorbers (Chapter 10).
m mLoose stabiliser bar (Chapter 10).
m mBroken or sagging springs (Chapter 10).
m mFront or rear wheel alignment (Chapter 10).
Erratic steering when braking
m
mWheel bearings worn (Chapter 1).
m mBroken or sagging springs (Chapter 10).
m mLeaking wheel cylinder or caliper (Chapter 9).
m mWarped discs (Chapter 9).
Excessive pitching and/or rolling around corners
or during braking
m mLoose stabiliser bar (Chapter 10).
m mWorn shock absorbers or mounts (Chapter 10).
m mBroken or sagging springs (Chapter 10).
m mOverloaded vehicle.
Suspension bottoms
m
mOverloaded vehicle.
m mWorn shock absorbers (Chapter 10).
m mIncorrect, broken or sagging springs (Chapter 10).
m mDefective power hydraulic system or leaking rear shock absorbers
(Chapter 10).
Cupped tyres (wear on both edges)
m mFront wheel or rear wheel alignment (Chapter 10).
m mWorn shock absorbers (Chapter 10).
m mWheel bearings worn (Chapter 10).
m mExcessive tyre or wheel runout (Chapter 10).
m mWorn balljoints (Chapter 10).
Excessive tyre wear on outside edge
m
mInflation pressures incorrect (Chapter 1).
m mExcessive speed in turns.
m mFront end alignment incorrect (excessive toe-in). Have
professionally aligned.
m mSuspension arm bent or twisted (Chapter 10).
Excessive tyre wear on inside edge
m
mInflation pressures incorrect (Chapter 1).
m mFront end alignment incorrect (toe-out). Have professionally
aligned.
m mLoose or damaged steering components (Chapter 10).