The device (1) has a pressure medium reservoir (Z1) for temporary storage of compressed air. A control side (Z) of a relay valve of a driver brake valve (D) is subjected with the compressed air for adjusting process by the operation of a manual control part. A valve device (SV1) is controlled by the pressure of a main air supply (HL), and subjects the control side of the relay valve from the reservoir. The valve device comprises a 2/2-way valve (SV2) and a pressure switch solenoid valve combination controlled by pilot pressure (Cv) or brake pressure (C) against the operation of a spring unit.
