4 ton Lincoln floor jack

[Dadstoy]

Ive got a old 4 ton Lincoln floor jack. Model # 93657. The hydraulic cylinder is leaking where the ram exits the cylinder. The jack works fine when filled with fluid but it leaks out overnight. Can I repair the hydraulic cylinder with a new O ring or do I need to have it rebuilt? Is this something I can do?

 

[930dreamer]

Hopefully the jack experts will chime in.

 

[alan camby]

Might want to take a picture of where the leak is. This would help the experts.

If the jack completely drains down over night. I would be concerned how long the seals inside have set without oil over the years.

P.S. I am not a expert

Edit: Just read your post again. Think I would do a complete rebuild if you have to go in that far.

 

[Smiliesafari]

Hydraulic jacks are a pretty simple devise. I have two old Blackhawk SJ2's. I've had them apart several times to replace various 'O' rings and pump seals. The only thing that makes it a job is they have to be completely disassembled. In order for the repair to be successful the ram has to be in excellent condition.

 

[Alaric.H]

I put new O rings on my 40 year old jack and it leaked no more it is not a hard job. A rebuilder wanted 300$ to do it so that's why I tried it. The worst I could do is lose the 50$ the rebuild cost.

 

[Hiball]

If your jack leaks completely dry when just sitting idle, is generally a reservoir issue. I would first inspect the bottom of the jack, to see if there have been any rubbing issues, paying close attention to where the tank nut meets the reservoir. If there is fresh oil on the Ram or weeping on the inside of where the tank nut seals, this is a indication that the main ram seal is probably compromised and it will need to be further disassembled to evaluate the problem. Hydraulic jacks are funny creatures.. Especially these 93657's I've seen situations where the pump pistons are leaking and the oil will start there and run the entire length do the unit and make you think that they are leaking from the ram end.

 

[Dadstoy]

No damage to the underside. Only wet at the ram end.

 

[469 runner]

Try tightening the packing nut to compress the O-ring a bit. The packing nut probably uses a special tool...just use a large pipe wrench, gently. Good Luck.

 

[Dadstoy]

I'll try that .

 

[Hiball]

Try tightening the packing nut to compress the O-ring a bit. The packing nut probably uses a special tool...just use a large pipe wrench, gently. Good Luck.

I'm fairly certain the OP's jack doesn't use a inner compression style tank nut.. Instead it uses a quad ring that sits in a machined groove. Secondly the ones that do, don't use orings under the nut, they use packing.

 

[Dadstoy]

There is a large nut where the ram comes out. Is that where the O ring or packing is located? Just unscrew it and replace the O ring or packing. That seems to be a fairly simple job if that's where the leak is. It doesn't seem to be wet toward the other end at all.

 

[Hiball]

There is a large nut where the ram comes out. Is that where the O ring or packing is located? Just unscrew it and replace the O ring or packing. That seems to be a fairly simple job if that's where the leak is. It doesn't seem to be wet toward the other end at all.

That is called the tank nut, it is what holds the reservoir to the base... As I stated earlier, if your getting large amounts of seepage here. The Main ram seal has more than likely failed, the tank nut "quad ring" isn't designed to hold back lots of oil, especially high pressure blow by. It's not quite as simple as just unscrewing the nut/replacing etc.. You will have to dismantle the jack, pull one side of the frame completely off to allow the unit to be removed. The only way to determine what really is going on, consists of tearing it apart.

 

[Dadstoy]

UM. Bummer. Well the jack is worth the repair. I guess I'll tear into it when the weather and temperature cooperates. My garage is unheated and its 21 degrees outside with nearly a foot of snow on the ground. Thanks for the help.