bottle jack limited function (squishy feel)

WI Dan · Jan 12, 2022

I have a bottle jack that pumps normally for about an 1" of lift. Then, nothing.

When it's empty (no load) it pumps normally, up higher and higher. But if i press down on it, it feels like a squishy balloon. Seems like it's full of air instead of non-compressable fluid.

How do I fix this?

Charles in Aus. · Jan 12, 2022

It sounds like it's a little low on hydraulic fluid . Pull the rubber grommet out of the side and fill with fluid until it starts to weep out of the hole . Open the valve and cycle the lift pump 8 or ten times to purge air . Replace grommet and test somewhere safe .

WI Dan · Jan 12, 2022

Thanks Charles. I will try this.

Steve in VA · Jan 12, 2022

In addition to Charles' fluid suggestion,
it may also be that the bleed-down screw
isn't seated so it pumps up under no load
but can't go any further.

Steve@Advance · Jan 12, 2022

Sounds like it's low on oil.

Usually a rubber plug about 2/3 way to the top, fill it to the plug sitting
upright, ram down. ATF, RO hydraulic oil, or jack oil will work. AW hydraulic
oil can damage polyurethane seals, so I hear.

Before putting the plug back in, jack it up, then push it down, see if it will
take more oil.

The plug can be a challenge to get back in, usually start it in sideways and
push it in with a small screwdriver.

caterpillar guy · Jan 13, 2022

I've tried Charles program then they would get a vacuum and not go up with oil in them if I left the plug out it would go up just fine. If I run it up then put the plug in it would build pressure when down and push up part way. Never have found a good way to solve hydraulic jacks except to send in or junk them and get a different one. I have 3 20 ton jacks and only 1 is any good anymore.

Charles in Aus. · Jan 13, 2022

Caterpiller guy , I suspect the vacuum the jack is developing is down to a faulty check valve ( just a small ball bearing and a weak spring ) or a blocked orifice due to some contaminant in the fluid.
I have fixed a few jacks just by draining the oil in them , flushing with new oil , then filling again . The amount of debris that comes out of some is surprising for what should be a closed system .

This post was edited by Charles in Aus. on 01/13/2022 at 03:57 am.

Russ from MN · Jan 13, 2022

Add some oil! And then you will have to cycle it a few times to get the air out of it, you waited too long!

bottle jack limited function (squishy feel)

WI Dan

Well-known Member

Charles in Aus.

Well-known Member

WI Dan

Well-known Member

Steve in VA

Well-known Member

Steve@Advance

Well-known Member

caterpillar guy

Well-known Member

Charles in Aus.

Well-known Member

Russ from MN

Well-known Member

Similar threads