Wheel cylinder with seal groove in bore of the housing

摘要

A wheel cylinder assembly (22) for drum brake system. The wheel cylinder assembly includes a housing (40) that defines a piston bore (50). A seal groove (54) that is sized to receive an annular seal is formed into the piston bore. A piston (42) is disposed in the piston bore and through the seal such that the seal sealingly engages both the housing and the piston. The construction of the wheel cylinder is such that honing and/or roller burnishing of the piston bore is not required. The piston (42) has an outside diameter (70) with a surface finish having a roughness less than about 0,8 mu m Ra. <IMAGE>