OK - in the past few hours, here's what I've learned:
1) My hydraulic pump is definitely leaking, and it's definitely coming from the filler cap. I lifted it up then used the manual drop to bring her down so I could watch from up front. Sure enough, there came the fluid.
2) I know the fluid level was relatively close, as I'd just refilled and checked it. It measured to within an inch on the top of the hydraulic cylinder after adding ATF.
3) I adjusted the descend speed to what I believe is the absolute LOWEST it will respond to. I know this because I initially went too far, and the solenoid that triggers the lowering valve was not functioning. I backed out the cap screw until it just BARELY made contact - lowered it - and still saw fluid coming out the filler cap/vent cap.
Because it was late (and dark), I didn't refill it and try the lowering procedure in short bursts - but according to the PO, if it's lowered in short 2- or 3-second bursts, the fluid won't come gushing out.
Could there be air in the lines causing all this?
Furthermore, I timed the lift time this evening just to give me a benchmark. 40 seconds with the lower fluid level, 37 seconds once I'd filled the reservoir. Granted, the battery might be less than 100%, but it had been on the charger for about 2 hours at that point. Not sure what state my battery is in, honestly - but it was purchased brand new just last week.
Just as a point of reference, I looked at an '83 Hi Lo, 21' model - and it raised and lowered PERFECTLY - literally the 12-second lift/lower, just as promised in the near 30-yr-old literature. Granted, the owner was very detail oriented, and knew how to care for his stuff, which I'm not sure I can say for the PO of my '94 Funlite.
Here's my concern: if the lifting/lowering takes so much pampering/babying, what's going on? Why is this not working as it should be? Where's the bottleneck in this whole system? I can't find any other ATF leaks anywhere, so I'm rather convinced it's losing all its fluid out the filler cap.
And another detail - the hyd. pump cycles through loud "squealing" sounds as it's raising the upper; it becomes louder, then cycles through it, then maybe 12-15 seconds later, here it comes again. I noticed it maybe 3 or 4 times during the lifting cycle. Any thoughts on this? Is that air in the lines? It sounds as though the hyd. pump is working much harder during these times. It may not be, but it sounds like it is.
Bend lift rod underneath? I haven't noticed it. And wouldn't that make it squeal/howl at roughly the same time in the lift cycle each time? That's not necessarily the case with this thing.
That's a lot to toss out there - but I'd love to know what you think.