Update: I got down in there again last night and tried with all I could to get the exhaust or inlet valve to move by hand. No luck. The only thing I can figure is that the inlet valve is stuck open and the exhaust valve is stuck closed. Explaining why the lift raises as soon as you let go of the clutch with the PTO on, even if the control is in the down position, does this seem correct?
Secondly, I hooked up the back blade for weight and looked in with the PTO running. There's about a 1/4" stream of fluid running down from what I think is the ram cylinder. This explains why the arms fall down on their own.
So my thinking is that I have to fix that leak and I have to unstick or replace the two valves, and clean out everything, at a minimum. I think I have to concede to dropping the whole pump and cleaning it thoroughly and pulling the cylinder out also to repair that.
I'm assuming I should find out EVERYTHING that's wrong before I start taking stuff apart? I haven't drained any fluid to this point, so how much oil do I need in there to operate the pump and still be able to find additional leaks? As of now I'm still unable to see what's going on very well due to the fluid.