Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
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HOMESERVICE MANUALSJAGUAR2000XJR (X308) V8-4.0L SC (AJ27)REPAIR AND DIAGNOSISBRAKES AND TRACTION CONTROLTESTING AND INSPECTIONPINPOINT TESTSPINPOINT TEST G: EXCESSIVE BRAKE PEDAL EFFORT
2000 Jaguar XJR (X308) V8-4.0L SC (AJ27)
Pinpoint Test G: Excessive Brake Pedal Effort
2000 Jaguar XJR (X308) V8-4.0L SC (AJ27)SECTION Pinpoint Test G: Excessive Brake Pedal Effort
G: EXCESSIVE BRAKE PEDAL EFFORT
G1: CHECK BRAKE PADS
1. Check the brake pads for wear, contamination, correct installation, damage and type.
^ Are any concerns found?
-> Yes
INSTALL the front brake pads correctly or INSTALL new front brake pads if necessary. REPEAT road test.
-> No
Go to [G2]
G2: CHECK VACUUM
1. Disconnect the vacuum booster hose from the booster.
2. Connect a vacuum/pressure tester to the vacuum hose.
3. Run the engine at normal operating temperature.
4. Record the vacuum reading.
^ Is the reading 40.5 kPa (12 in-Hg) or greater?
-> Yes
Go to [G3]
-> No
LOCATE and REPAIR the source of low vacuum. TEST the system for normal operation.
G3: INSPECT SYSTEM
1. Switch the engine off.
2. Reconnect the vacuum hose.
3. Inspect the brake booster, rubber grommet, and all vacuum plumbing for cracks, holes, damaged connections, or missing clamps.
4. Pump the brake pedal several times to exhaust the vacuum. Push down on the brake pedal and hold.
^ Does the brake pedal move down when the engine is started?
-> Yes
Vacuum system is OK.
-> No
Go to [G4]
G4: CHECK POWER BRAKE BOOSTER VALVE
1. Check the brake booster valve.
^ Is the power brake booster valve OK?
-> Yes
CHECK the brake booster.
INSTALL a new brake booster if necessary. TEST the system for normal operation.
-> No
INSTALL a new brake booster valve. TEST the system for normal operation.
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- β’ You smell fuel, burning insulation, or see smoke.
- β’ Brakes feel soft, pull hard to one side, or make grinding noises.
- β’ The engine overheats, stalls repeatedly, or misfires under load.
- β’ You are missing required tools, torque specs, or safe lifting equipment.
- β’ You are not confident in the next step or safety outcome.