An actuating system 1 for a wheel brake system of a motor vehicle, wherein the braking action is obtained by means of a rotatable cam element 2 fixed to the motor shaft 8 of an electric motor, with said rotatable cam element 2 abutting against an actuating member 4, so as to laterally displace said actuating member 4, resulting in the braking pads 5 being pressed against the friction element or brake disk. Recovery or adjustment of the backlash or gap arising due to the wear of the brake pads. The motor-cam group or assembly is displaced so as to keep the brake pads 5 in light contact with the friction element or disk but without exerting any unwanted braking action.