Abstract: A master cylinder having a body (10) with a bore (12) therein in which slides at least a primary piston (20). The primary piston (20) has a compensation passage (58), which in a position of rest, places a pressure chamber (24) in communication with a reservoir (14). The communication between interrupted upon actuation of the master cylinder by a control rod (18) acting on a second piston (48) sliding in the bore (12). A first compression spring (28) and a second compression spring (42) urge the primary piston (20) and second spring (16) toward a rear position of rest. The preload force of the first compression spring (28) exceeding that of the second compression spring (16) such that the second piston (48) is the first to move in response to a force applied to the control rod (18). The rear position of rest for the primary piston (200 and second piston (48) is defined by a same stop (36) which is integral with the body (10) of the master cylinder.

Abstract: A disk brake having at least one piston (14) which slides in a caliper (12), the caliper (12) sliding over a stationary support. The piston (14) being actuateable by a mechanical subassembly (22) having substantially first (24) and second (26) parallel plates. The first plate (24) being driven in rotation by a lever (32) about an axis (X--X') perpendicular to its surface. The second plate (26) being held in a stationary position with respect to rotation and secured to piston (14). A face on at least one of the first (24) and second (26) plates has a groove formed therein for receiving balls (28) to convert rotational movement of the first plate (24) into axial transulational movement of the second plate (26). The lever (32) has a first part (34) fastened onto an end (36) of a sheath of an actuating cable (38). The sheath (40) bearing on an end stop member (42) which is held stationary with respect to the caliper (12). The sheath (40) has an end stop member (42) which is formed on a brace member (44).