Hydraulic jack question

Rich'sToys · Aug 30, 2023

The other day I was hauling my tractor home and, unfortunately, blew a trailer tire. Sadly, the 10 ton hydraulic bottle jack I carry for such situations decided to only go up about an inch and stop working. I got help changing the tire, but now am wondering about that jack. I'm assuming it's low on oil, as I think I saw some on the floor where it had been sitting in the shop.
Does it take a special oil, or will anything work? How about hydraulic fluid? If that doesn't solve it, is there a fix for it, or should I just chalk it up and buy a new one?

DanielW · Aug 30, 2023

You can get special 'jack oil', but any hydraulic oil, TDH fluid, or even ATF will do just fine. A lot of the newer jacks don't have a fill plug. Or if they do, it's a pressed-in plug that's not meant to be removed. You can usually knock them out with a
chisel to fill up and goop them back in-place with some hardening gasket maker - they're on the low-pressure side of the jack so doesn't need to hold any pressure. Just be careful: if fluid leaked out before, it will leak out again. Probably only a very
slow leak - just don't rely on it to hold a load overnight (or over your head without additional blocking). Usually the seals start leaking when the rod gets a little scarred/pitted/rusty - usually from the jack being left partially extended. The rods on
a lot of bottle jacks aren't chromed, so they rust when left extended. Then when they're retracted, that little bit of surface rusts cuts up the seals just a little.

chcase · Aug 30, 2023

If it is a normal bottle jack you can buy
a bottle of jack oil at any hardware
store. If you have air in your jack a
simple thing to do is raise the jack till
it stops then drop it but not shut the
valve then pump the handle 10 to 15
strokes then shut the valve then see if
works ok. Make sure jack is full of oil
first.

Andy Wickiser · Aug 30, 2023

You can take them apart and try to fix them. However new ones are so cheap that
it doesn't make sense unless you are curious/stubborn/sentimental etc. Look for
seals/kits on eBay, the Web etc.

Below is an old one I took apart recently. Label says ''All Pump Parts are
Easily replaceable''. However rod and bore dimensions were odd and I couldn't
find a main seal no matter how hard I looked. Actually main seal still looked
O.K. and wasn't overly hardened. The jack acted like yours - wouldn't lift a
load. Problem wasn't fluid level, did the same thing when filled to spec. I used
common tractor trans-hydraulic fluid I see no reason that shouldn't work.
Problem might be check valve, release valve, pump seal etc., maybe later I will
fool with it some more.

<IMG SRC =https://i.postimg.cc/GmbKkgCz/Bottle-Jack-Disassembled.jpg>

Stephen Newell · Aug 30, 2023

Use jack oil. It's available nearly everywhere. If that doesn't work better just get another jack. you would have to take the old jack apart and replace the seals and O rings. More work than it's worth.

Hydraulic jack question

Rich'sToys

Well-known Member

DanielW

Member

chcase

Member

Andy Wickiser

Member

Stephen Newell

Well-known Member

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