Improvement to return piston in disc brake stirrup for motor vehicles by incorporating bleed hole venting to atmosphere between joint seal and a return ring

摘要

The stirrup of a disc brake consists of a hydraulic cylinder (4) a piston (5), defining a hydraulic chamber (6), a joint seal (7) and a return ring (8). The seal and the return ring (8) are placed between the piston (5) and the cylinder (4) and are lodged in the grooves (97,98), the groove (97) for the joint seal (7) being placed nearer to the hydraulic chamber (6). Between these two seals is a bleed hole (40) venting to atmosphere.