Abstract: The invention relates to a hydraulic brake system of a vehicle comprising one wheel brake valve preceding each wheel brake cylinder and one return feed pump connected parallel to each of the wheel brake valves and connected to the suction sides of the wheel brake cylinders. For anti-lock control, the return feed pump is put into operation, and by clocked triggering of a wheel brake valve of a vehicle wheel that is tending to lock, the brake fluid pressure in the wheel brake cylinder of this vehicle wheel is modulated. To realize a traction control device, the invention sets forth a switchover valve in a brake line from the master brake cylinder to the wheel brake cylinder of a driven vehicle wheel.

Abstract: The invention is based on a dual-circuit anti-lock vehicle brake system (10) with a tandem master cylinder (12), a switchover valve (14) following the latter, a brake pressure modulation valve assembly (18, 20) that has a brake pressure buildup valve (18) and a brake pressure reduction valve (20) for each wheel brake cylinder (16), and a return pump (24). To enable building up brake pressure rapidly for vehicle dynamics control, the invention proposes one additional pump (28) in each brake circuit (I, II), whose intake side is connected directly to the master cylinder (12) and which feeds in the direction of the wheel brake cylinders (16) connected to to this brake circuit (I, II). As a result, a brake pressure buildup is possible in each wheel brake cylinder (16), even when the master cylinder (12) is not actuated, which buildup can be modulated for individual wheels in a manner known per se.