Brake Master Cylinder: Description and Operation

The brake master cylinder is a dual-piston type.

The brake master cylinder is assisted by a power brake booster.

The following conditions are considered normal, and are not indications that the brake master cylinder is in need of repair or replacement:
^ 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 to compensate for normal brake wear. Add brake fluid as needed.

A momentary or slight ripple of brake fluid inside the brake master cylinder reservoir upon application or release of the brake pedal.
^ A trace of brake fluid found on the outside of the power brake booster below the brake master cylinder mounting flange. This condition results from the lubricating action of the brake master cylinder wiping seal.