An electric brake system for braking a vehicle, the system comprising - a central transmission gear configured to rotate around an axis (A) to transmit mechanical energy between an electric brake motor and a brake actuation mechanism to activate or deactivate braking of the vehicle by rotating the central transmission gear in a brake activating direction (B) or brake deactivating direction (C), respectively; - a first engagement member mechanically fixed to, or integral with, the central transmission gear to rotate with the central transmission gear around the axis (A); - a second engagement member configured to selectively engage or disengage the first engagement member depending on a position of the second engagement member along the axis (A); - a parking brake actuator configured to move the second engagement member along the axis (A) for switching the position of the second engagement member between a service brake position (S) and a parking brake position (P), wherein o in the service brake position (S) the first and second engagement members are mechanically disengaged, and the central transmission gear is free to rotate independent of the second engagement member for freely transmitting the mechanical energy between the electric brake motor and the brake actuation mechanism ; and characterized in that o in the parking brake position (P) the first and second engagement members are mechanically engaged to prevent the central transmission gear from rotating in the brake deactivating direction while allowing rotation of the transmission gear in the brake activating direction. - a central transmission gear configured to rotate around an axis (A) to transmit mechanical energy between an electric brake motor and a brake actuation mechanism to activate or deactivate braking of the vehicle by rotating the central transmission gear in a brake activating direction (B) or brake deactivating direction (C), respectively; - a first engagement member mechanically fixed to, or integral with, the central transmission gear to rotate with the central transmission gear around the axis (A); - a second engagement member configured to selectively engage or disengage the first engagement member depending on a position of the second engagement member along the axis (A); - a parking brake actuator configured to move the second engagement member along the axis (A) for switching the position of the second engagement member between a service brake position (S) and a parking brake position (P), wherein o in the service brake position (S) the first and second engagement members are mechanically disengaged, and the central transmission gear is free to rotate independent of the second engagement member for freely transmitting the mechanical energy between the electric brake motor and the brake actuation mechanism ; and characterized in that o in the parking brake position (P) the first and second engagement members are mechanically engaged to prevent the central transmission gear from rotating in the brake deactivating direction while allowing rotation of the transmission gear in the brake activating direction. o in the service brake position (S) the first and second engagement members are mechanically disengaged, and the central transmission gear is free to rotate independent of the second engagement member for freely transmitting the mechanical energy between the electric brake motor and the brake actuation mechanism ; and characterized in that o in the parking brake position (P) the first and second engagement members are mechanically engaged to prevent the central transmission gear from rotating in the brake deactivating direction while allowing rotation of the transmission gear in the brake activating direction. <EOS>