With proper and regular maintenance, this hydraulic jack can be used for a long time without leaking. Rotate screw up when height is not enough. Use it uprightly, not edge-on or upside down. Features: Enlarged base ensures stable and safe using. Oil return valve operation is simple, convenient and quick. Whole body casting, thickened steel plate. Long time use and does not leak. Skid resistance lines on the top. Oiling Maintenance: 1. Put jack in vertical state. 2. Lower the pump and piston, until it is completely loose. 3. Remove the rubber oil plug. 4. Pour into high quality hydraulic oil. 5. Mount rubber oil plug. 6. Regular lubricate transmission joint and adjusting screw.