Abstract: A hand held manually operable hydraulic auxiliary device for lifting or pressing of loads or for operating of tools includes a hydraulic cylinder having pressure and activating pistons disposed between which is a valve housing including inlet and discharge channels and being furnished with non-return valves.The hydraulic cylinder including both the actuating piston operable by a manually operated lever, and the pressure piston, as well as the valve housing are disposed within an outer casing receiving the hydraulic fluid. The outer casing at least on the pressure piston side thereof is provided with a tool adapter. The valve members include a forced reset guide. Disposed in the area of the pressure side of the hydraulic cylinder is a randomly operable detent.