1990 Jaguar XJS Brake Service (ONLINE REPAIR MANUALS)

XJS

• Raise and support rear of vehicle.
• Remove nuts and bolts securing tie-plate to rear suspension unit. Remove tie-plate.
• Ensure parking brake lever is in fully OFF position. Lift carpet adjacent to handbrake lever mounting for access to cable adjusting nuts. Fig. .
• Loosen cable lock/adjusting nuts.
• Release springs from parking brake caliper arms (1) Fig. .
• Move right hand arm to center of vehicle, enabling end of inner cable (2), to be detached from operating arm.
• Slide rubber cover from outer cable (3) and release outer cable from other parking brake operating arm.
• Position...

XJS

Front

Do not remove or attempt to remove bolts securing halves of caliper together.

• Remove spring clips (1), retaining piston dust covers (2). Fig. . Remove dust covers (3).
• Carefully feed compressed air into caliper brake line port. Remove pistons from caliper.
• Carefully pry each seal (4) Fig. , from recess in each piston cylinder bore.
• Thoroughly clean all components using brake cleaning fluid.
• Examine pistons and cylinder bores for signs of abrasion, scuffing, scratches or corrosion. If any of above conditions are evident, a new caliper must be use.
• Coat new seals with brake lub...

The hydraulic booster increases pedal force by means of hydraulic pressure. The dynamic circuit of the rear brakes is supplied from the hydraulic accumulator via a control valve in the booster.

The pressure in the booster and rear brake circuit is proportional to the pedal force. The booster is composed of an actuating piston (1), and a booster piston (2), Fig. .

The movable , mechanical connection between the control valve (3) and two pistons is made by means of a scissor-lever mechanism (4), Fig. .

The control valve (3) opens the pressureless booster chamber to the reservoir (9). Sim...

ACCUMULATOR, REPLACE

• Discharge hydraulic accumulator by depressing brake pedal until it becomes difficult to operate (approximately 20 times).
• Place a shop rag or towel around accumulator area to absorb any spilled fluid.
• Remove accumulator, then discard O-ring.
• Reverse procedure to install, noting the following:
• Install New O-ring on accumulator, then install and torque accumulator to 29.5-34 ft. lbs.
• Turn ignition switch to On position, then wait until accumulator is charged to upper cut-out point and ABS warning light goes out.

ACTUATION UNIT, REPLACE

• Discharge hydraulic accumulator b...

XJS

Front

Do not remove or attempt to remove bolts securing halves of caliper together.

• Remove spring clips (1), retaining piston dust covers (2). Fig. . Remove dust covers (3).
• Carefully feed compressed air into caliper brake line port. Remove pistons from caliper.
• Carefully pry each seal (4) Fig. , from recess in each piston cylinder bore.
• Thoroughly clean all components using brake cleaning fluid.
• Examine pistons and cylinder bores for signs of abrasion, scuffing, scratches or corrosion. If any of above conditions are evident, a new caliper must be use.
• Coat new seals with brake lub...

Bleeding the ABS system is not a routine maintenance operation and should only be necessary when part of the system has been disconnected or the fluid is contaminated.

During the bleeding procedure, it is important that the level of fluid in the reservoir is maintained at approximately 2mm below the bottom of the filler neck. Motor/pump unit cannot charge accumulator if air, and not fluid, is standing on low pressure side of pump.

If motor/pump unit, fluid intake hose, or hydraulic unit of ABS system has been removed or disconnected, bleed as described under "Fluid Intake Hose."

For ...