Floor jack repair

[Patrick L]

So my old Craftsman 2 ton floor jack seems to need help. It won't "hold" the lift. And If I just raise it with no weight on it, if I step up my own weight will slowly bring it down.

I've looked at lots of YouTube videos, but what I don't get is, do I need to do a full rebuild? Or is there an easier fix? Sort of like , first check this, then this, etc.

Some videos would imply it could be as easy as air in the system that needs to be bled. Or possibly I just need to add jack oil.

I guess I'm looking for someone with experience with these to give me a check list. If it ends up I need a full rebuild, so be it.

Its an older jack, so I'm thinking it is worth fixing as opposed to just getting a Harbor Freight replacement. Plus, I did get it from the estate of a favorite uncle, so there is sentimental value too.

[jim 44-40]

Bet it is the O-ring,

[HWooldridge]

Yeah, they wear over time and seals start leaking; they also can run low on oil and you’ll get air in the lines.

[Patrick L]

Would I necessarily see some sort of oil leak? That's the thing, most of the YouTubers said if it was a seal or ring I would either have a puddle under the jack from leakage/drippage, or I'd see something leaking as the jack was dropping.

Thanks for all your help!

[Winger Ed.]

I've worked on several pallet jacks that did the same thing and have the same sort of mechanism.
If the 'O' rings are good, sometimes you can just flush them out with new oil.

Make sure its oil is full.
If so, it's probably a little dirt or something in the little check valve that stops oil from
flowing back into the reservoir. It's normally a seat that looks sort of like a carberator main jet with a ball bearing on it.

Bad 'O' rings usually don't seal and let oil back into the reservoir when you try to pump it up.
If a 'O' ring is bad, most good hardware stores have a decent selection and you can match it up.

[jsizemore]

Check your oil level on the body which holds the ram and cylinder. If the oil level is good and it's not leaking on the floor you could have any of the following:

1.Bad cup on the ram
2.Cylinder scored
3.Release or lowering valve stem or o-ring could be bad
4.Relief valve ball, seat, or spring could be bad
5.Debris (usually parts of o-ring) are hung and blocking seal of #'s 3 and 4

When we got them for repair (authorized repair shop and sales) they were tore down of all their parts, non steel parts and springs were cleaned in a solvent tank and steel parts soaked in warm caustic soda tank. Cylinder got honed and polished and painted parts repainted factory color. Depending on the jacks capacity, it had to maintain it's rated capacity overnight. If it passed the test, it's work order # was stamped on the jack boss and stickers attached.

You hate doing a rebuild and debris that didn't get flushed from the innards cause it to fail again. We also repaired timber equipment and ship steering gear.

[lightman]

We have a local machine shop that repairs them. Maybe call around and see what you can find.

[Patrick L]

Thanks all!

[45DUDE]

I have had 4 good floor jacks repaired over the last 20 years and none lasted for more than a year. Save some grief and get a low profile fast pump. When you get something jacked up put jack stands under it and let down. Rubber made in China sucks. You don't even have to use it and it rots in a year. A good jack has about 8 0rings and most people that rebuild them can see which one it is and that's all that gets replaced.

[farmbif]

all hydraulic seals have a cure date and life expectancy. if you decide to take it apart and replace seals and o rings, degrease and clean everything real good even before you try to open it up it can safe frustrations. motion industries and Grainger are a couple places that still have local outlets in case you not certain how to measure or describe the rubber parts inside.

[PopcornSutton]

Go to HomeShopMachinist.net. Do a search and there is an old thread about getting repair parts.

[Brassmonkey]

I have an old Lincoln 2ton floor jack, it's been with me for 24 years, got the seals redone in 2005 and it's due again. Cost me 80$ in 05. Probably 180 now, still worth it to me.

[DougGuy]

Far be it from me to even (cough cough) suggest an import, BUT... Your old Craftsman if it's 1980s is likely Taiwan made, at least the cylinder that does the lifting is. That said, you can buy a new import with low profile, more ergonomical operation, much more lifting capacity, for less than the cost of rebuilding the old one. They have "Nascar-ized" the look, feel, and operation of the current spate of floor jacks for the home shop. I have one old 3 ton 1980s model that is heavy, noisy, but it has yet to fail me.

Also, worth mentioning, vehicles have taken a lower profile stance so the jacks need to be lower to be effective. If I had to replace mine now, I would just get an import from HF and save the receipt. They have gotten up to speed on their warranty so it's not the risk it used to be.

Besides that, if you think a Chinese made jack is junk and turn your nose up at it, just wait until the world crises erupts farther, people will be emptying the shelves of anything they can get their hands on, once that happens, IF it does, it would make that Chinese floor jack you wouldn't dare own, look mighty appealing about now.

[country gent]

It sounds like the release valve is dirty pr scored from over tightening . O rings or the cuo wear slowly with just your weight visible dropping it the valve may be the issue. I would start by draining the jack remove the valve and look it over good for scoring then flush out the seat and clean the valve. Pal attention to the tapered area and o rings. O rings show wear in the form of a visible flat spot around them where they seal.
These are a one way cylinder ( gravity down) if the valve dosnt cure it then remove the piston an look for scoring in the barrel and flat spots on the o rings. If these are leaking by it can be internal and not show any leaks. Light scoring can be removed with a cylinder hone sometimes but polishing it removes material lightening the o ring seal force.

[G W Wade]

My Craftsman floor jack needs oil every once and a while. Lift the cover plate and you will find a rubber plug at the base of the cylinder. fill with jack at lowest position GW

[abunaitoo]

Hardest part is finding the correct O-rings.
Lots of times, it's the seat for the release ball.