Disc brake assembly having a diaphragm pressure compensator and seal

摘要

A self-adjusting rear disc brake assembly provided with a parking brake to mechanically actuate the disc brake, as well as having hydraulic service brake actuation, has a confined air space between the outer piston and the inner piston. The pressure compensator and seal embodying the invention operates to maintain the confined air space substantially at ambient air pressure while preventing contamination of the brake actuating mechanism by air borne contaminants normally encountered in the area of a vehicle rear brake mechanism.