A fluid powered vehicle seat adjustment system comprising a fluid actuator a source of pressurized hydraulic fluid and a controller. The fluid actuator including first and second inlet/outlet conduits, and the controller selectively controlling and directing pressurized fluid selectively to either the first or second inlet/outlets of the actuator. The actuator further comprising actuator isolation valves associated with each of the first and second inlet/outlets of the actuator. Each actuator isolation valve allowing a flow of fluid from the actuator only when pressurized fluid is supplied to the actuator and other isolation valve in order to prevent movement of the actuator except when pressurized fluid is supplied to the actuator.