A parking and emergency brake device having an actuating device (10) that is supplied with pressurized fluid wherein a piston (14) slides in a cylinder (12, 22) to axially delimits a front hydraulic pressure chamber (16) and exert a determined mechanical force on an operating member over an actuating travel and a valve (18) to selectively place the front pressure chamber (16) in communication with a pressurized hydraulic fluid supply port (20). The valve (18) is interposed between the piston (14) and the cylinder (12) to controlled by an axial movement of the piston (14) over a control travel prior to actuating travel.