Jack leak at pump/piston

[jackedup]

Hello, I have a jack with a leak at the pump/piston pictured. I am not sure on the jack model which if anyone knows would also be appreciated.

Are there any gaskets on this piston or things that I should check? The Jack raises but does not to seem to go all the way, maybe 90%. It holds for a while then you hear leakage.

 

[jackedup]

A few more pictures. I checked the Jack again and it probably goes up closer to 75% and takes a lot of pump action to get to that level. Is this a sign of simply bleeding and refilling? I know it has not been in use for over 5 years

 

[paulsomlo]

If you pull the pump piston on that, you'll find an oring and some backup rings made of hard plastic - they're not on the piston, but rather in grooves in the bore.

Here's a thread that will address pretty much any question you have: https://www.garagejournal.com/forum/threads/overseas-jack-rebuild-help-tutorial.51105/

 

[jackedup]

If you pull the pump piston on that, you'll find an oring and some backup rings made of hard plastic - they're not on the piston, but rather in grooves in the bore.

Here's a thread that will address pretty much any question you have: https://www.garagejournal.com/forum/threads/overseas-jack-rebuild-help-tutorial.51105/

Thank you for the link. Do I need to identify the pump model / manufacturer first though? I am sure I could match the o-rings from ones I have on hand but not the plastic collar if that needs replacement

 

[paulsomlo]

Thank you for the link. Do I need to identify the pump model / manufacturer first though? I am sure I could match the o-rings from ones I have on hand but not the plastic collar if that needs replacement

From the looks of the label, an ID may be difficult. The plastic collar is probably OK - but if you need parts, try this place, from member Hiball's signature: "Need a Seal Kit? Contact Hydraulic Parts Supply at 620-594-2247"

 

[jackedup]

I took the next step and removed the handle in piston. There is two plastic pieces on the end of the piston. I have posted pictures below. One is a thin plastic washer and the other is a more cup style spacer. The white washer was split so that it could go on but I am not sure if that is a natural split. When removing the white washer the brown washer fell apart almost instantly upon touching it.

The brown washer has the following writing "UHS 1 1.2" and another spot looks like it says "4AV" but I am not sure.

 

[paulsomlo]

Well, once again, I've been proven wrong - but I think you're in luck; a search on "UHS11.2" brings up lots of options and they're all inexpensive. It looks like the standard size on that is 11.2mm on the ID, 19.2mm on the OD, and 5mm on the height - if you've got a caliper, go ahead and confirm those measurements. Otherwise, the seal should measure about 7/16" on the ID, 3/4" on the OD, and a little over 3/16" on the height. The white washer, aka "backup ring" can be reused.

In your initial post, you said it holds for a while then you hear leakage - do you mean the lift arm drops slowly when it shouldn't? If so, the seal in your main ram is also compromised.

 

[jackedup]

Well, once again, I've been proven wrong - but I think you're in luck; a search on "UHS11.2" brings up lots of options and they're all inexpensive. It looks like the standard size on that is 11.2mm on the ID, 19.2mm on the OD, and 5mm on the height - if you've got a caliper, go ahead and confirm those measurements. Otherwise, the seal should measure about 7/16" on the ID, 3/4" on the OD, and a little over 3/16" on the height. The white washer, aka "backup ring" can be reused.

In your initial post, you said it holds for a while then you hear leakage - do you mean the lift arm drops slowly when it shouldn't? If so, the seal in your main ram is also compromised.

Thank you for the help. I have been watching various repair videos and I was surprised to see the gasket as well but glad it had numbers on it. The arm does not drop but you hear gurgling noises as it leaks from the piston. I am still trying to clean up the jack to see if the main is also leaking.

 

[paulsomlo]

If the arm does not drop, then you're probably in luck - just order the seal for the pump. But do be aware, that if one seal is compromised, the other may be not far behind. Of course, it's possible that the other one was replaced along the way - you'd have to know the history on it.

 

[jackedup]

Thank you for the help. I have been watching various repair videos and I was surprised to see the gasket as well but glad it had numbers on it. The arm does not drop but you hear gurgling noises as it leaks from the piston. I am still trying to clean up the jack to see if the main is also leaking.

I don't have a caliper but the measurements you mentioned seem spot on

 

[jackedup]

Finally received my gasket (I have 4 backup) from overseas and it fits perfectly. Definitely the correct size and the leak on the piston seems to be gone so far. Jack now goes up all to its full extension.

 

[paulsomlo]

A happy ending!