A load-dependent four-circuit brake system is equipped with a hydropneumatic spring system, in which each spring leg includes a connection to a brake pressure regulating valve. In addition to the pressure applied by the brake pedal to the brake pressure regulating valve, also a part of the pressure prevailing in the spring leg is applied to the brake pressure regulating valve and the spring leg pressure acts, with a predetermined position of a relief valve slide member, on the brake cylinder corresponding to the respective position of the brake pedal.
The circuit controlls a fluidically controlled brake regulator (7) in dependence on the load of a vehicle having at least two wheels each provided with a suspension member (1, 2). Each suspension member (1, 2) cooperates with a fluidic pressure sensor (11, 12) to control the regulator (7) in dependence on the load carried by only one of the wheels, namely the wheel carrying the lighter load.
