A couple of months ago the rack and pressure line in my 84 5000S REALLY started to leak....like the can of Pentosin I had been buying weekly ceased keeping up with the leak. So, I replaced the rack, pressure and return lines. The problem I have is that since replacing all that, the pump now has what I would call a "Ford" type of whine. Many mid 90's Ford's I've owned/driven all had this high-frequency whine when putting the steering off center-providing boost. The steering feels ok, other than being able to feel the whine through the wheel a bit, but I have no loss of assist, or any leaks. I bled the system per the factory manual before I drove it after replacing the rack/lines, and last night I cracked the pressure line @ the pump to see if there was any air trapped. It didn't seem like there was any air. Is there another bleeding procedure other than how the manual says?? I just hate to think that I'm slowly killing this pump....car only has 64k & I'd like to fix this annoyance!!!!

 

It kind of sounds like during all the keeping up with the leaking, it may have gotten one of the seals in the pump and it's causing a cavitation of sorts inside.