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. Refer to Power Brake Booster Replacement .

Fluid leaking between the brake master cylinder and the power brake booster indicates damage to the power piston seal (4). Damage may reduce the power assist. Replace the hydraulic brake booster. Refer to Power Brake Booster Replacement .

A fluid leak between the 2 housings indicates a damaged housing seal (7). Replace the hydraulic brake booster. Refer to Power Brake Booster Replacement .

Damage to the relief valve seal (2) allows fluid to leak past the relief valve. Replace the relief valve.

Damage to the spool valve plug seal (3) allows fluid to leak past the spool valve. Replace the hydraulic brake booster. Refer to Power Brake Booster Replacement .

Damage to the accumulator seal (5) allows fluid to leak past the accumulator cap. Replace the accumulator seal (5) with the power brake booster on the vehicle. Refer to Power Brake Booster Replacement .

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

Tighten
Tighten the return port fitting (1) to 10 N·m (88 lb in).

If the leak continues, replace the seal ring under the return port fitting.

For information on diagnosing the brake warning system, refer to Brake Warning System Description .