DC - it's the strangest thing I've ever seen. Third set of parts - new everything, and still with symptoms. Since the shop did their thing to it, the pump doesn't moan and whine any more, so I'm guessing there's no longer air in it, but fluid is still sloshing around the reservoir pretty good.
I'm so disgusted, I'm thinking of selling it. Got a guy coming to look at it today, jerry-rigged PS setup and all.
The other thing I might do is swap in a pump from a 4.0, with the reservoir attached, the less lines, the better. Will see if I can dig one up at the boneyard.