Wheel Cylinders

Wheel cylinders push drum brake shoes against the drum. They are small, inexpensive and fail frequently through seal leaks and internal corrosion, especially in humid climates and on vehicles where brake fluid is rarely changed.

Specify by OEM number, axle position and side, bore diameter (often expressed in fractions of an inch on Japanese vehicles), inlet and bleeder thread, and mounting bolt pattern. Left and right cylinders are frequently mirror images and are not interchangeable. Workshops commonly replace cylinders when fitting new brake shoes because a leaking cylinder contaminates new linings. Cylinder repair kits containing cups and dust boots are a lower-cost alternative in some markets.