Braking system for motor vehicles

The braking system has a master braking cylinder operated in dependence on the depression of the brake pedal via a braking servo and coupled to at least one wheel braking circuit, which can be supplied with a brake fluid volume independent of the operation of the brake pedal when a given loading (A,B,C,D) of the wheel braking circuit is reached and the required retardation reaches a corresponding threshold value (a1,a,2,a,3,a4).