Abstract: The invention provides a vehicle suspension device comprising an actuator (10) having a piston (11) and a plurality of chambers (A and B), a source of pressurized fluid (21), an exhaust for pressurized fluid (24), a first sensor (34) senses the force applied to the actuator (10), a second sensor (35) senses the pressure of the fluid supplied by the source of pressurized fluid (21) and a controller (23,27) controls the extension of the actuator (10) by controlling the flow of fluid to and from at least one of the chambers (A, B), the controller (27) receives signals from the first (34) and second (35) sensors and controls the actuator accordingly.