Bleed air from a hydraulic floor jack by extending the piston, opening the pressure release valve, removing the oil fill port, replacing the port, and repeating until no more air escapes from the oil fill valve. Bleed hydraulic jacks regularly to keep the jack in proper working condition.Continue Reading
Insert the handle into the jack, and pump it until the piston fully extends. Do not proceed until you are certain it is at its maximum length.
The pressure release valve is located near the base of the jack. It is the valve you open to retract the piston. Insert a flathead screwdriver into the head of the valve, and turn counterclockwise one-half turn. The piston should automatically retract at this time.
The oil fill port is on the side of the jack, but similar in looks to check valves. Check the owner's manual to determine the correct screw to loosen. Do not loosen the check valves. Insert a flathead screwdriver into the slot, turn it counterclockwise, and remove the plug. You should hear air hissing as you remove the plug. Replace the plug.
Repeat the process of extending and retracting the piston and opening the port until you no longer hear air hissing out of the opening when you release it.