Abstract: Construction in order to improve wear-resistance of a hydraulic fluid chamber in which a clutch release-actuating tubular piston is operative within a cylindrical housing made of a resin-based material reinforced with glass fiber, the piston axially driving a clutch release bearing to force a clutch diaphragm spring to release the clutch of a motor vehicle power train. A sealing member is provided on tile piston for sealing piston-driving hydraulic fluid within the fluid chamber. The cylindrical housing is double-walled, defining the axially extending tubular fluid chamber. A layer of nickel is electroless-plated at least along the fluid chamber bore where the sealing member slides; alternatively stainless steel linings are installed along the corresponding portions of the chamber bore.

Abstract: A release mechanism for a pull-type clutch which is disengaged by pulling an inner peripheral part of a diaphragm spring (6) to an axial backside of the clutch. A release bearing assembly (10) is connected to the inner peripheral part of the diaphragm spring (6). A cylinder assembly (11) is mounted to a housing (12) of the clutch at an axial backside of the release bearing assembly (10). The release bearing assembly (10) is connected to the cylinder assembly (11) through means of a connecting ring (60) and a stopper (70).