Abstract: A master cylinder with increased safety having a piston produced by molding a plastic or aluminum alloy. The piston slides in a bore blocked off by an end wall. A valve for the master cylinder bears at rest against a pin that is fixedly mounted in the body of the master cylinder passes through the piston via a longitudinal slot. The dimensions of the master cylinder are determined such that the piston bears against the pin before coming into contact with the end wall of the master cylinder body.

Abstract: A master cylinder with increased safety having a piston produced by molding a plastic or aluminum alloy. The piston slides in a bore blocked off by an end wall. A valve for the master cylinder bears at rest against a pin that is fixedly mounted in the body of the master cylinder passes through the piston via a longitudinal slot. The dimensions of the master cylinder are determined such that the piston bears against the pin before coming into contact with the end wall of the master cylinder body.

Abstract: A pneumatic brake booster for a motor vehicle having a rigid casing (1) with a moving partition (2) to define a front chamber (11) and a rear chamber (12) therein. A pneumatic piston (3) carried by the moving partition (2) has a bore which retains a three-way valve (6). The three-way valve (6) is connected to an actuating rod (4) which acts on a plunger (5) to connect the front chamber (11) to the rear chamber (12) with a first pressure in a rest position and connects the rear chamber (12) to a second pressure in an actuation position. In the actuation position, a pressure differential develops across the movable partition (2) to create a boost force which is transmitted to a push rod (7) through a reaction disc (9) retained in a cup (8) to develop a braking force in response to an input force applied to the actuating rod (4). An intermediate member (10) located between the cup (8) and plunger (5) slides with respect to the piston (3) and plunger (5).