Jaguar XJ (X350). Manual - part 159
Brake caliper piston(s)
Parking brake module
Parking brake caliper piston(s) Parking brake switch
Brake discs
Damaged or corroded wiring harness
Wheel bearings
Brake master cylinder fluid level switch
Brake pads
Adjustable pedal motor
Power brake booster
Adjustable pedal switch
Brake pedal linkage
Brake booster vacuum hose
Tires
Debris
Adjustable pedal drive cables
Carry 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 comparisons 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 detect performance concerns.
An experienced brake technician will always establish a route that will be used for all brake diagnosis
road tests. The roads selected will be reasonably smooth and level. Gravel or bumpy roads are not
suitable because the surface does not allow the tires to grip the road equally. Crowned roads should
be avoided because of the large amount of weight shifted to the low set of wheels on this type of
road. Once the 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 suspected condition.
From the description, the technician's experience will allow the technician to match possible causes
with symptoms. Certain components will be tagged as possible suspects while others will be
eliminated by the evidence. More importantly, the customer description can reveal unsafe conditions
which should be checked 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.