Okay, so I think I finally found my problem. I had a really slow week at the shop so I was able to take a solid block of time to tear the Jubilee top apart again.
With it running I pinpointed the fluid leak coming from area at the gap between the lift cover and the tractor case. I initially thought it was from the backpressure valve, but after I tightened it up it made no difference.
-on a side note, I also figured out how it works- that you turn the threaded section from the outside of the case and the pickup tube turns ON it on the inside. Mine has been seized all this time, so if I turned the threaded housing on the outside, the pickup tube would swing back and forth a little, but would make contact with all the innards of the case, so it wouldn't actually make a full rotation. Despite my worry of breaking a part I couldn't replace, I had to just give it the beans before it broke loose and turned.-
So, anyhow- I took the cover off, cleaned out the big tube that goes from the bottom of the hyd case to the valve body on the cover, thinking it was clogged or something. It wasn't. I had a LOT of white foam from around that general area, like there was a lot of pressure squeezing fluid out of somewhere. Upon a MUCH closer investigation, I saw what looked like a section of blue gasket missing from in between the lower half of the valve body and the lift cover. I took it off, and sure enough, about a .5" piece of the gasket has blown out. I'm pretty sure this is my problem with the whole thing, and it makes sense as to why it worked great one second and then didn't work at all. Hopefully the local Tractor Supply has one on the shelf so I can get this thing back out into the field this afternoon.
