Brake Master Cylinder

Check the brake tubes and brake master cylinder (2140) mounting. The brake tubes and brake tube nuts must be tight without any signs of leakage. Tighten the brake tube nuts (2133) at the brake master cylinder to 22-28 Nm (16-21 lb-ft).

The following conditions are considered normal and are not indications that the brake master cylinder is in need of service:

• Low brake fluid level detected without signs of leakage. This condition is caused by displacement of brake fluid from the brake master cylinder reservoir into the disc brake calipers (2B120) and/or the rear wheel cylinders (2261) to compensate for normal brake wear. Add brake fluid as needed.
• A momentary or slight squirt of brake fluid from the brake master cylinder reservoir upon application of the brake pedal (2455). This condition is caused by brake fluid displacement through the brake master cylinder reservoir compensating port as the brake master cylinder pistons move forward in the bore when the brakes are applied.
• Slight turbulence in the brake master cylinder reservoir fluid when the brake pedal is released. Turbulence occurs as brake fluid returns to the brake master cylinder after releasing the brakes.
• A trace of brake fluid found on the outside of the power brake booster (2005) below the brake master cylinder mounting flange. This condition results from the lubricating action of the brake master cylinder wiping seal.