Abstract: A master cylinder is described. The master cylinder includes a chamber delimited by a piston and supplied from a brake fluid reservoir installed on the top of the master cylinder by an end fitting engaged in a nozzle on the body of the master cylinder. The piston has a nose of reduced section upstream of its skirt guided in the bore hole of the master cylinder and the nozzle is connected to the chamber by a drill hole issuing into the chamber at least partly upstream of the piston in rest position. A valve module is installed in the drill hole to manage communication between the reservoir and the chamber as a function of the position of the piston and the pressure in the chamber with respect to the pressure in the reservoir.

Abstract: A master cylinder is described. The master cylinder includes a chamber delimited by a piston and supplied from a brake fluid reservoir installed on the top of the master cylinder by an end fitting engaged in a nozzle on the body of the master cylinder. The piston has a nose of reduced section upstream of its skirt guided in the bore hole of the master cylinder and the nozzle is connected to the chamber by a drill hole issuing into the chamber at least partly upstream of the piston in rest position. A valve module is installed in the drill hole to manage communication between the reservoir and the chamber as a function of the position of the piston and the pressure in the chamber with respect to the pressure in the reservoir.

Abstract: A method is described for detecting an incorrectly installed seal in a master-cylinder having a seal. The master cylinder is subjected to a pressure comprised between approximately 0.3 and 0.6 MPa at the conclusion of master-cylinder assembly and, if there is a drop in the pressure, the seal is considered to have been installed in reverse in the groove of the master cylinder.

Abstract: A method is described for detecting an incorrectly installed seal in a master-cylinder having a seal. The master cylinder is subjected to a pressure comprised between approximately 0.3 and 0.6 MPa at the conclusion of master-cylinder assembly and, if there is a drop in the pressure, the seal is considered to have been installed in reverse in the groove of the master cylinder.

Abstract: Our problem relates to a master cylinder with a U-shaped seal. Our goal is to avoid defective bleeding of hydraulic braking systems. The defects arise out of the fact that the vacuum causes the lips of the seal (21) to stick together and to stick against the wall (41). To achieve this, reliefs (42) will be created on one wall (44) of one lip (28) facing the other lip (27) and on the edge face (50) of this same lip. These reliefs will prevent the lips from sticking tightly to one another and to the wall facing the edge face of the lips. This lack of sticking will prevent a vacuum from being created between the two lips and between the edge face of the lips and the wall (41). As a result, the seal will be able to return to a position in which bleeding can be performed effectively.

Abstract: Our problem relates to a master cylinder with a U-shaped seal. Our goal is to avoid defective bleeding of hydraulic braking systems. The defects arise out of the fact that the vacuum causes the lips of the seal (21) to stick together and to stick against the wall (41). To achieve this, reliefs (42) will be created on one wall (44) of one lip (28) facing the other lip (27) and on the edge face (50) of this same lip. These reliefs will prevent the lips from sticking tightly to one another and to the wall facing the edge face of the lips. This lack of sticking will prevent a vacuum from being created between the two lips and between the edge face of the lips and the wall (41). As a result, the seal will be able to return to a position in which bleeding can be performed effectively.