Device for controlling the braking of vehicles, comprising: - a pumping device of a work fluid comprising a body wherein at least a seat is formed having ▪ at least a first stretch having at least a first port for delivery, and at least a second port for delivery separate from said first port; ▪ at least a second stretch having at least a supply port, connectable to a work fluid storage tank, and at least a third port for delivery; where said first stretch has a smaller diameter than said second stretch; where inside said seat is slidably housed a piston, movable by the braking pedal of the vehicle, adapted to define a first chamber inside said first stretch communicating with said first and second ports (6, 13) and a second chamber inside said second stretch communicating with said third port, said piston being movable between an idle position, wherein said supply port is communicating with said second chamber and at least a first braking position, wherein said second chamber is isolated from said supply port; - a first line for braking communicating with said first port and connectable to the braking system of a vehicle; - a second line for braking communicating with said second port and connectable to a user point; - a third line communicating with said third port and with said first line; characterized in that it comprises first valve means arranged along said first line for braking to allow the flow of the work fluid towards the braking system of the vehicle as a result of the achievement of a predefined pressure difference at its extremities, said third line being in communication with said first line downstream of the first valve means, second valve means adapted to allow the return of the work fluid from said first line for braking towards said first chamber during the displacement of said piston from the first braking position towards the idle position, and third valve means arranged along said third line adapted to prevent the return of the work fluid inside said second chamber. - a pumping device of a work fluid comprising a body wherein at least a seat is formed having ▪ at least a first stretch having at least a first port for delivery, and at least a second port for delivery separate from said first port; ▪ at least a second stretch having at least a supply port, connectable to a work fluid storage tank, and at least a third port for delivery; where said first stretch has a smaller diameter than said second stretch; where inside said seat is slidably housed a piston, movable by the braking pedal of the vehicle, adapted to define a first chamber inside said first stretch communicating with said first and second ports (6, 13) and a second chamber inside said second stretch communicating with said third port, said piston being movable between an idle position, wherein said supply port is communicating with said second chamber and at least a first braking position, wherein said second chamber is isolated from said supply port; ▪ at least a first stretch having at least a first port for delivery, and at least a second port for delivery separate from said first port; ▪ at least a second stretch having at least a supply port, connectable to a work fluid storage tank, and at least a third port for delivery; where said first stretch has a smaller diameter than said second stretch; - a first line for braking communicating with said first port and connectable to the braking system of a vehicle; - a second line for braking communicating with said second port and connectable to a user point; - a third line communicating with said third port and with said first line;