Vehicle brake system with two brake circuits

The vehicle brake system (10) has two brake circuits and at least one wheel-brake. The fluid pressure on the at least one wheel brake is controlled by a fluid-control component group (38,40,42,44,46,48;24) which is connected by at least one brake conduit (50,52,54,56) to the at least one wheel brake. A sensor (58) registers the breakdown of a brake circuit.