Thanks, I'll look at it tonight.
When I put the truck back in the shop last night the power steering started acting up too. Turning the steering wheel to one side or the other caused the wheel to respond pretty erratically, either trying to pull harder or do little or nothing at all. I thought about it some and it's not really the hydroboost unit itself that seems to be an issue. I had a friend look at it with me last night and the noise is coming from the pump.