It’s frustrating when you need to lift something with your trusty floor jack, but discover that your previously reliable jack will only lift part-way, or not at all. Othertimes, the jack might be stuck in a lifted position and won’t lower.
For those encountering a stuck jack for the first time, having your jack stuck in the up or down position can elicit the kind of choice language that generally upsets our mothers, and ruins your plans to work on your car or truck.
The good news is that it’s usually* a fast and easy fix, and our friends at Sunex have made a short and accessible video for floor-jack maintenance which should help you solve your trapped-air problem as well as show you how to lubriate your floor jack properly to keep it in tip-top shape for the next time you need it.
(* – sometimes the universe conspires against you, and neither we nor the capable tool experts at Sunex can help you if you’re on the Cosmic Naughty List.)
How to Bleed Air Trapped in a Hydraulic Floor Jack
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.
1. Rotate, or spin, handle to the right until it stops.
2. Back it up two turns to the left.
3. Pump the jack 10-15 times to release trapped air.
4. Turn the handle all the way to the right to close the relief valve.
Afterward, jack functionality should be back to normal. Now, get to work!
How to Properly Lubricate a Hydraulic Floor Jack
1. Acquire grease.
2. Apply grease to key floor jack components, which are the following:
- Lift arm pivot pin
- Axles on front wheels
- Bearings under caster wheel bracket
- Back rollers which come into contact with pump plungers
- Universal joint near release valve
- Handle base on inside surface of the female handle receiver (must remove handle to access)
I learned some thing new today!!!!! I did not know how to get air out of floor jack.. what I did was open fill hole an with pump not under any pressure would jack the handle a few times an watch the air bubbles..
i rebuilt my old sears hydraulic floor jack, 328-12002. the jack would lift UP even in the RELEASE POSITION
and won’t RELEASE back down.
did I possibly install the RAM SEAL the wrong way on the shaft?
So after replacing the old Ram piston seal, Jack lifts fine but even after air bleed process won’t go down. This is a craftsman 328.12291 3 ton Jack…when trouble shooting this the only way to get the Jack down is unscrew the check ball screw(the flat head screw to the left), but then all the hydraulic fluid purges out…now what?
If I understand this correctly, the oil fill plug must be removed to do the air purge.Is this correct?
Thank you!!! I thought I’d have to rent a crane & crane operator to get my lawn tractor down! Lol I’m tired, hot & sick. Not in the mood for all that!
Wow, thanks dude! I was mad at my teenage son when our neighbors moved last year they gave him a 40’s era heavy duty floor jack that’s sat on my carport for months seemingly stuck forever in up position. Works great now!
My floor jack will lift when I push down on the handle but before I am push it back down it wii already be down. Can’t get it to lift anythingBobby mcafee
Jack went up. Will not come down. No screw on side. Handle will only turn left/right an inch or two. Phillip screw on top of piston. Loosend it and removed it-looks like where you add oil. Slot head screw on housing. Removed it, but nothing happened.
Hi,I tried all the instructions as per video but still my jack wont lift. I’ve topped up the hydraulic fluid level tried everything still no luck, what could be the problem?
jack wont go up filled it with oil moves a little bit but falls wont pump up ?
Did you check for leaks? Particularly weeping around the seals?
My jack doesn’t have a bleed valve it has just a plug should I keep it loose to allow air to escape
My jack doesn’t have a bleed valve it has plug should I take out or leave it loose
Your procedure don’t work