A leveling jack for a vehicle, such as a recreational vehicle, includes a leveling piston and cylinder, a bi-directional, reversible pump, and a reservoir within a common sealed housing that does not require exterior fluid connections. The piston is extended from the housing to contact the ground and effect leveling by operating the pump in one direction, and is retracted into the cylinder by operating the pump in the other direction. Accordingly, the leveling jack is a self-contained unit, and does not require a central hydraulic unit and the necessary hoses between the jack and the central hydraulic unit as needed in the prior art.