Abstract: 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.

Abstract: A hydropneumatic pressure tank, whose housing consists of a bottom part and of a top part which are connected with each other by a welded seam; a retaining ring is arranged at the inner wall of the tank within the area of the welding seam, at which is secured the bellows serving as movable partition wall; at least the part of the retaining ring opposite the welding seam thereby consists of a layer rejecting the welding material.