Floor jack kaput

Twas about a year ago that I last used the floor jack.

I wanted to level a travel trailer and yup, the floor jack wouldn’t work.

A sissors jack buckled under the load.

Has anyone serviced a floor jack? what is involved and what kind of perils await me if I take it apart.

What kind of jack? Screw-type scissors? If the metal bent, toss it, get a new one.

Generally the only service I’ve ever done on a floor jack is changing the hydraulic oil. If the thing’s not lifting, you probably have a leak somewhere. It could just be that there’s some air in the system from a very slow leak that has let enough air in during the prolonged sitting, but it’s also likely that once you refill and/or bleed it, it’ll gush out of where ever the leak is. There should be a little bleed/fill screw you open up to check the oil level, add more if necessary and bleed the air out of the system. Open the screw and pump down, but close it before you get to the bottom of the down stroke. Repeat until you get all the air out.

However, I’ve only actually serviced the big professional-style 4-ton floor jacks at the shop I used to work at. If it’s anything less than a quality brand 3-ton, I wouldn’t mess with it and just go out and get a new one. And, just to remind everyone, you shouldn’t work under anything supported only by a brand new perfectly functioning floorjack, so obviously you don’t want to get under anything that’s only held up by this questionable jack.

There usually is a plug on the side of the hydraulic unit that can be removed to fill the reservoir. Stand the floor jack with the ram pointed upward. Look for a plug on the side of the bottle jack case. Unscrew or pop that plug. If the oil level is not at the openning fill it with hydraulic jack oil. That can be purchased at an auto parts store. Replace the plug; lay the jack back down; cycle it up; and let it down a few times. When you no longer hear any ‘snaps’ on let down, try lifting something to see if it will work again.

If a low reservoir was the problem, you might consider storing the jack with the ram pointed upward.

Hope that helps

Yeah, I’ve rebuilt a few hydraulic jacks I was particularly fond of over the years. It’s not much different than a snow plow lift ram in construction, if you’ve had any experience there. The difficulty is in finding replacement O rings and/or packing nuts for the ram. Although if you’re handy and persistent, it’s not a big deal. What I would do is first refill the reservior and then pump it up with a load so you can locate the leak if it’s external. If it can’t hold a load and isn’t leaking externally, then the internal seal(s) are bad. The difficulty in finding parts is directly proportional to the origin of manufacture and age of the jack. That being said, I have never been stumped trying to locate soft parts.

Super slow leaks over time may not require immediate attention. The reservior eventually gets low enough that the ram can’t be extended. Just add more fluid and keep an eye on it from then on. But the safe bet is to rebuild it.