OT-Floor Jack

[rws]

I had an old cheap floor jack jack in my shed for years, and never used it until yesterday. I jacked the front of my truck up on one side then set blocks under it, but left the jack in place. I left it there over night and today, it was all the way down and now it will not arise and stay up. I don't see oil on the ground, but the jack won't hold itself up.

I look under it, and it is nothing more than a bottle jack configured to work horizontal. The base is made to bolt onto the frame, the valve and plunger on top. So what is in this? A cylinder with packing/seals, seals on the plunger, and a seal at the valve? Can't be much more than that. Any idea where parts could be bought? It's broken now, can't hurt it much more!

I did a search here, didn't see anything about actually replacing parts on a jack like this.

[Alistair Hosie]

Sounds like it might be air in it rather than a loss of oil. Try bleeding it I think try turning it upside down also just check the oil level anyway. I am no expert but I just got mine working great with a good oil fill. Alistair

[Willy]

Try the easy stuff first.
If it's been stored out of it's intended orientation of operation it may very well need to be bled.
Takes longer to explain than to do.
If you've got a minute and a half to spare take a look at this short YouTube link.


https://www.youtube.com/watch?v=gH7u5WMFGBg

[wierdscience]

Like Willy said,try bleeding it first and if it needs oil,be sure and use actual jack oil and not just anything lying around.

If you do end up taking it apart,do so carefully and note where all the check balls and valve parts go.They are very simple machines,usually just a piston seal and a pump seal and that's it for wear parts.

These folks will have nearly anything you could need-

http://www.hcrcnow.com/shop/parts

[Arcane]

If you managed to jack your truck up I doubt it needs bleeding. If it will rise up and then fall back down there is a high probability that the main seal on the piston has failed. Cheap jacks are cheaply built and it's likely the seal didn't have full rear support and cracked right where it flexed as pressure pushed it against the piston. I say this because I've seen it happen.

[rws]

Arcane, I was thinking the same thing, if it went up once, I doubt there was an air lock in it.

Weirdscience, thanks for that link! There had to be some place that had parts for these type of things.

[garyhlucas]

There are two check balls, one on pump intake, one on pump discharge and the lowering valve is a bypass from the cylinder to the tank. A leaking valve, or a bit of dirt in check balls could also cause this.

[metalmagpie]

use actual jack oil and not just anything lying around

Or use AW32 hydraulic fluid, which you can conveniently buy at any auto parts store. As far as I'm concerned, draining out the old fluid, filling with new fluid and then bleeding fixes many cheap cylinder problems.

metalmagpie