Follow the procedure below: – remove and rebuild the hydraulic pump. – loosen the differential case with a 9/16 inch open-end wrench and the Ford Plow Wrench or a 1-1/16 inch wrench. – inspect it for any leaks or damage, and replace any necessary parts. – check for any other sources of leaks that may be present in the system. This includes checking for leaky axle seals, brakes, and lower lift pins. – remove the pump and replace it with a new one. – replace some of the components in your hydraulic lift system such as rod connections or control valve spools. – consider replacing your hydraulic lift cover repair kit which includes 2 1/2 inch O rings.