A hydraulic brake force booster for vehicle brake systems comprises a reservoir (300) for the collection and storage of a fluid pressure. The reservoir is connected to a fluid source and receives fluid from this, simultaneously forming a fluid pressure. In addition the reservoir is connected to the brake force booster (20) via a one-way or non-return valve (330), which normally interrupts the fluid connection from the reservoir to the booster. The non-return valve can be opened according to the pedal pressure exerted and then makes a corresponding connection between the reservoir and the brake booster. A further one-way or non-return valve (26) is located between the fluid source and the brake booster and prevents any return flow. <IMAGE>
