Vacuum Booster Seal Leak Diagnosis

INPUT ROD SEAL
A fluid leak from the inside of the driver's compartment at the power brake booster vent hole indicates a damaged input rod seal (6). Replace the hydraulic brake booster.


POWER PISTON SEAL
Fluid leaking between the brake master cylinder and the power brake booster indicates damage of the power piston seal (4). This can possibly reduce the power assist. Replace the hydraulic brake booster.

HOUSING SEAL
A fluid leak between the two housings indicates a damaged housing seal (7). Replace the hydraulic brake booster.

RELIEF VALVE
Damage to the relief valve seal (2) causes fluid to leak past the relief valve. Replace the hydraulic brake booster.

SPOOL VALVE PLUG SEAL
Damage to the spool valve plug seal (3) causes fluid to leak past the spool valve. Replace the hydraulic brake booster.

ACCUMULATOR SEAL
Damage to the accumulator seal (5) causes fluid to leak past the accumulator cap. Replace the accumulator seal (5) with the power brake booster on the vehicle.

RETURN PORT FITTING

NOTICE: Refer to Fastener Notice in Service Precautions.

Tighten the return port fitting (1) to 10 Nm (88 inch lbs.). If the leak continues, replace the seal ring under the return port fitting.