Raybestos WC37639 Rear Drum Brake Wheel Cylinder is a PG Plus Professional Grade hydraulic actuator for drum-brake systems. It converts brake-fluid pressure from the master cylinder into the outward force that pushes the rear brake shoes against the inside of the drum, enabling reliable braking when installed as part of a rear drum-brake assembly. The part is identified by WC37639 and is designed for use as a rear-wheel component in vehicles equipped with drum brakes that require this specification.
