A hydraulic fluid system including a master cylinder (30) moved by a clutch pedal (34) for pressurizing a remotely located slave cylinder (50). The slave cylinder and master cylinder each including a rolling diaphragm (104, 176). The slave cylinder further including a cup-shaped piston (134) for isolating its rolling diaphragm from the rotation of a throw-out bearing (66) which is moved by the diaphragm.