Seal Leak Diagnosis

Input Rod Seal





A fluid leak from inside of the driver's compartment at the power brake booster vent hole indicates a damaged input rod seal (5). Replace the hydraulic brake booster. Refer to Hydraulic Brake Booster Replacement Hydraulic Brake Booster Replacement.

Power Piston Seal
Fluid leaking between the brake master cylinder and the power brake booster indicates damage of the power piston seal (3). This can possibly reduce the power assist. Replace the Hydraulic Booster Refer to Hydraulic Brake Booster Replacement.

Housing Seal
A fluid leak between the two housings indicates a damaged housing seal (6). Remove and disassemble the power brake booster. Replace the Hydraulic Brake Booster. Refer to Hydraulic Brake Booster Replacement

Spool Valve Plug Seal
Damage to the spool valve plug seal (2) causes fluid to leak past the accumulator cap. Replace the Hydraulic Brake Booster. Refer to Hydraulic Brake Booster Replacement.

Accumulator Seal
Damage to the accumulator seal (4) causes the fluid to leak past the accumulator cap. Replace the accumulator seal (4) with the power brake booster on the vehicle. Refer to Hydraulic Brake Booster Accumulator Replacement.

Return Port Fitting

Notice: Refer to Fastener Notice in Service Precautions. If the leak continues, replace the seal ring under the return port fitting.

Tighten
Tighten the return port fitting (3) to 10 Nm (88 inch lbs.).