What causes a hydraulic jack not to work?
Both having too little and too much hydraulic oil can cause a floor jack to malfunction. Make sure that your floor jack always has oil up to the oil line and not too far above or below it. Lubricate your floor jack. Add oil to all moving parts to make sure that nothing is stuck and everything is moving smoothly.
How do you fix a jack that won’t go up?
How do you troubleshoot a hydraulic floor jack?
Why does my floor jack not go up?
The most-common reason a floorjack would be stuck in the up or down position would be because of air trapped within the hydraulic pump, preventing the jack from having full range or lifting/lowering capabilities. You need to bleed or purge the air from the jack, which isn’t difficult once you know how.