Cork gasket leak, maybe?

[twoton]

Originally Posted by Sam Mac

.... The later pumps ....:

Originally Posted by ol'George

... the return oil does flow through the bearing on the later units....

What is the criteria for 'later'?

[ol'George]

They have no drain back hole in flange where the cork gasket lives.
That would denote the later style.

[twoton]

Thank you.

[finsruskw]

How long did it sit before the leak became apparent?
How did you identify and find where it WAS NOT leaking from??
Just curious as to whether you used the baby powder test or not.
That usually tells you exactly where the leak/s are by leaving a trail right to the source,

[ol'George]

When solving a problem, if you input the same numbers, you will get the same answer. If expecting a a different answer, that is stupidity. You feel you have done a good job of sealing the 'ol korky gasket, 2X, so look elsewhere. Obviously it is leaking closely to that area but is it really coming from the gasket surfaces or the expansion plug under it or above the gasket surface area?
Go powder yer ass-end.---- to be sure
I know it is frustrating BTDT. For me, once it was the expansion plug below, and another time it was the one of the relief valves above that had a compromised "O" ring. Is it possible that the cork gasket area is somehow being kept away from compressing the gasket properly to get a good seal?

To back up:
When did the leak originally start? recently, last year, you purchased it leaking? Just trying to get more input so to add up different numbers to solve the problem.
Is there a crack somewhere in the rear end or the hydro, that normally just don't happen? Think outside of the box. There is a trail of oil leading to the source, that only you can find.

[West Valley G]

Upon further investigation. This machine had at least one hundred leaks when
I bought it 10 years ago. I am actually down to this one. One would think
that would make me thrilled, it does.
Certainly the cork gasket was leaking after I repaired it the first time.
It is now fixed on round 2. I believe the leak I am now seeing more then
likely is the left side trunnion seal.
The next best thinking to powdering your hind end is to put a couple
hours on the seat in dusty patch of garden. On a nice clean rear end it
was easy to see a fine trail of oil coming from that seal. I looked those
seals over well initially but just didn't see it leaking, oh well.
Been reading a bunch of archives here and can't quite figure out.
Can I pull the rear end again and replace that seal or does the pump
have to come apart to do that fix. That would scare me lots.
Thanks much for help all. I sure learn a bunch.

Ken

[Ambush]

You can drill a small hole in it , thread about a #8 screw into it and pull on the screw with vice grips. Sometimes you need two screws.

[finsruskw]

That will work on the right side seal but not on the left.
Read the FSM for more details on that seal replacement.

Good luck!!

[ol'George]

You can replace 3 out of the 4 seals exteriorly, without dissembling the hydro
The seal behind the trunnion requires total disassembly.
Might just learn to live with a "little dribble" now and then, and I don't have to
describe that.

[Ambush]

At the hydraulic shop I worked in, we called that "Criminal Engineering".