Patent ID: 6959547

Claim:
A master cylinder intended for an electrohydraulic braking system, of the type comprising: a body ( 12 ), defining a primary pressure chamber ( 14 ) and a secondary pressure chamber ( 16 ), separated by an axially movable piston ( 22 ), the so-called secondary piston; means ( 28 ) for the hydraulic connection of the primary pressure chamber ( 14 ) with braking-force simulation means ( 30 ); and complementary moving and stationary means ( 32 , 34 ) for the sealing of the hydraulic connection means ( 28 ), and borne by the secondary piston ( 22 ) and the body ( 12 ) respectively, the secondary piston ( 22 ) being axially movable between a rest position, in which the moving and stationary sealing means ( 32 , 34 ) are spaced apart from each other, and a position in which said moving and stationary sealing means ( 32 , 34 ) are cooperating with each other, characterised in that the secondary piston ( 22 ) comprises two portions ( 22 P, 22 D), capable of an axial motion in relation to each other in order to adjust the relative axial position of the moving and stationary sealing means ( 32 , 34 ) when the secondary piston ( 22 ) is in its rest position.