Floor jack not holding under pressure

[robstaples]

My 3 ton floor jack will move its entire range with no load. When I tried to lift my tractor to add chains, it would " slip" and not lift. No oil leakage in its life at least where I stored it. I'm giving it away but thought "working" would be nicer. What is the most common failure for these symptoms ? It's Harbor freight. Probably used 20 times in 10 years.


Thanks in advance

 

[MAN IN BLACK]

My first reflex would be to check the oil level...looks like low oil symptom to me.

 

[k0ua]

My first reflex would be to check the oil level...looks like low oil symptom to me.

That is what mine does when it is low on oil.

 

[wdchyd]

If it goes all the way up it's not low on oil

if it is creeping down, it is either the main ram cup or a valve.......if it is the release valve (gear under handle) you can reseat it if you tighten by hand, then tap it with a hammer ONCE, then open release valve, pump up a few times and repeat the tap......ONCE. Also another tip is to take off handle (see the small knurled thumb screw not painted) and grease inside the handle socket....sometimes they get rusted and don't tighten up the release valve enough

If that doesn't do the trick then it is either the ram cup, a discharge ball valve, suction ball valve or overload valve.......in which case the dumpster and wallet can fix it easily

the old jacks (before the Asian knockoffs) were able to be rebuilt but one by one they went out of business and parts availability became scarce, jacks became a throwaway commodity