1835B pump seal leak …. Again

[Guinter810]

Hey everyone.

I paid a shop to put a new pump seal in where the shaft goes to the engine. Told him when I dropped it off to go over it check and make sure there is no bearing play or an issue with the shaft. He put a seal in it and leaked again as soon as got it home.

He's coming this week to put another seal in. I'm thinking there's another issue and it's pushing oil out of the seal, from what I read that seals there to keep dirt and stuff out of the pump. I have to put $80-100 of fluid in it everytime I use it, getting old and hurting my pockets. Leaks even when it's off. When I shut the engine down I can hear it spit air/fluid out for 1-2 seconds.

Is there anything to look for. Little research I did said to check the case drain. Anything else that could be causing the internal leak ? Or continuous seal issues

 

[foton]

you might want to look at the pressure the system is operating at , maybe the bypass is frozen, if your guy can check it out first so you do not just blow out another seal,I think would be the right move.

 

[Guinter810]

Thank you. I did recommend to him last time that he should check the pressures. Maybe even an obstructed case drain ?

Anyone know if these older cases have a fluttering valve. A co worker that worked at Cat mentioned that because of it spitting when you shut it off.

 

[foton]

yeah pump pressure reversing on turn off and trying to equilize in the system, poof .you would think that there would be some kinda flow direction valve

 

[Guinter810]

He came today. Made some calls. Checked out and verified its seeping oil out of the front pump seal again. He doesn't believe his seal is the issue. I told him if he doesn't think the seal is defective I don't want another big bill. He didn't check anything the 1st time he had it. He moved the pump assembly back, pulled the seal and installed the new one and shipped it.
So I have no idea what could cause the seal to be puking oil out. There's no pressure, it's dribbling out not shooting out. It'll drain the hydro tank out in 2 days not even running.

It's all on me now so I'm going to pull all the pumps out and see if I can figure out what's going on with that pump. The only thing I can think of is the shaft is walking in and out for some reason. Unless something else is causing excessive pressure in the pump …. This sucks

 

[Jim A]

Most often those are just dust seals not made to hold high pressure .
In pump there are wear compensation plates that with special plastic seals expand when pressurized at 3000psi etc.
If it is a gear pump or vane pump you can replace wear plates which press against pump gears to make the seal.
If worn sometimes you can lap plates on sheet of glass to remove scratches it must be a mirror like finish.
Look up parts break down of that pump.
I have done this on old machine s where others kept blowing low pressure shaft dust seals .
Good luck

 

[Guinter810]

Most often those are just dust seals not made to hold high pressure .
In pump there are wear compensation plates that with special plastic seals expand when pressurized at 3000psi etc.
If it is a gear pump or vane pump you can replace wear plates which press against pump gears to make the seal.
If worn sometimes you can lap plates on sheet of glass to remove scratches it must be a mirror like finish.
Look up parts break down of that pump.
I have done this on old machine s where others kept blowing low pressure shaft dust seals .
Good luck

Thank you!! I started pulling the pumps last night and was going to break down the pump and see what's going on. I'll definitely check into those plates.