Abstract: An industrial vehicle has a tool adaptor mounted on the outer ends of a pair of support arms. A self contained hydro-electric unit is mounted on the tool adaptor or on a support arm closely adjacent to the tool adaptor. The unit comprises a hydraulic reservoir, a hydraulic pump, and an electric motor which drives the pump to pass hydraulic fluid under pressure to one or more double acting hydraulic control cylinders to move an associated locking pin from a retracted position to a locking position wherein it engages a frame element of a tool to lock the tool in place in the tool adaptor.