Blowing pump seal

[WHE12 0]

I bought my first wheel horses couple months ago. When I looked at it the guy said he had the engine rebuilt so when he put the engine on he was checking everything and noticed it was low on transmision fluid. He put some in it and he said it lost it pulling power and he guess it was wrong fluid and sat for 2 yrs. 

when I got it how it started right up and ran perfect. It wouldn't pull a hill and after warmed up I had to help it the shop. So I drained the tranny fluid and flushed it, filled it with engine oil and new filter. 

 

First time messing with hydraulics I was nerves to take alit apart. 

I ended up resurfacing everything and welded the charge pump house. When I got it together and engaged the pump it blow a weak hydrulic hose. At the time I thought I could route it out of transmission and back into the return. But I was told to never do that agin. Then it blow the seal out of the pump. I fixed the old seal for further tests and I ended up running the line on rear of pump back into the fill and tapeing it so trash wouldn't get in. It's very strong now and thought I was good. Then I bought some orb to jic and replaced the blown line. Started it up and blow the old seal out. I don't know what's causing it and hoping somone could help out. 

I now have replace the seal with a new one and I've caped the top hydro line and the rear line is routed back into the fill. 

This is a 1970 electro 12 with a 90-2046 sundstrand pump

[R. L. Addison 299]

In my experience, blowing seals out of hydraulics is a sign of excessive leakage, or at least more leakage than the drain (return line) can handle. Are you getting piston pump volume into your charge system? Is your drain partially restricted some way? Hydraulics can be frustrating at times with a piece in wrong or some other simple thing sometimes. I would retrace and verify previous steps. There

should be manuals available and a world of info from this website. Such a website is invaluable!!