Braking system for vehicles comprising - a manual actuator device, operable by means of a lever and / or a pedal, selectively connectable to at least one braking device (16, 16') placed on a first axle of the vehicle, and at least one braking device (16, 16'') placed on a second axle of the vehicle, each braking device (16, 16', 16") acting on a respective brake disc or drum, - at least one front automatic actuator device, operatively connected to said manual actuator device by means of a first control unit, and to the at least one braking device (16, 16') of the first axle of the vehicle, - at least one rear automatic actuator device, operatively connected to the manual actuator device by means of a second control unit, and to the at least one braking device (16, 16'') of the second axle of the vehicle, - wherein said control units (32,40) are programmed so as to actuate the respective automatic front and rear actuator devices (28,36) as a function of the position or configuration of the manual actuator device, - wherein at least the front automatic actuator device is of the electric-hydraulic type and is connected to a first hydraulic delivery circuit of the manual actuator device, by means of a first shut-off valve positionable in an operating position, in which it hydraulically disconnects the front automatic actuator device from the manual actuator device, and in a safety position in which it hydraulically connects the front electric-hydraulic automatic actuator device with the manual actuator device; characterized in that the first shut-off valve is provided with a pair of non-return valves (80', 80"), in which a first non-return valve allows the discharge of any residual pressure left in the automatic hydraulic actuator devices, a second non-return valve has a filling function through connection with a brake fluid reservoir. - a manual actuator device, operable by means of a lever and / or a pedal, selectively connectable to at least one braking device (16, 16') placed on a first axle of the vehicle, and at least one braking device (16, 16'') placed on a second axle of the vehicle, each braking device (16, 16', 16") acting on a respective brake disc or drum, - at least one front automatic actuator device, operatively connected to said manual actuator device by means of a first control unit, and to the at least one braking device (16, 16') of the first axle of the vehicle, - at least one rear automatic actuator device, operatively connected to the manual actuator device by means of a second control unit, and to the at least one braking device (16, 16'') of the second axle of the vehicle, - wherein said control units (32,40) are programmed so as to actuate the respective automatic front and rear actuator devices (28,36) as a function of the position or configuration of the manual actuator device, - wherein at least the front automatic actuator device is of the electric-hydraulic type and is connected to a first hydraulic delivery circuit of the manual actuator device, by means of a first shut-off valve positionable in an operating position, in which it hydraulically disconnects the front automatic actuator device from the manual actuator device, and in a safety position in which it hydraulically connects the front electric-hydraulic automatic actuator device with the manual actuator device;