[davew833]

I thought about it being air in the P/S system because I just replaced the timing belt and water pump and disconnected the P/S return hose in the process. I hadn't noticed the problem before that.

I replaced the P/S tank O-ring, filled it up and cranked the wheel back and forth a bunch of times with no effect on the problem. Maybe I didn't do it enough to clear the air out of the system, or it's another problem.