Power steering whine

All,

My son and i have changed everything but the rack.

The dead spot ion the steering is gone but the rebuilt pump squeals louder than the bad one.

We have drained, bled, cycled the steering, everything that we have read about.

We put steering enhancer and still it whines loud.

I know this is a know 80's Ford "thing", but it shouldn't be louder than the turbo......

Any idea's are greatly appreciated.

Had a similar issue a number of years ago. PS had been very quiet for years, but suddenly started making horrible squealing noises along with fluid foaming in the reservoir. Tried bleeding the PS system MANY times, including putting a vacuum on the reservoir many times. No change in foaming or noise.

Only part left was the rack. Replaced the rack with a NEW (not reman) rack and the noise instantly vanished. My guess is one of the rack end seals developed a small leak and would suck in air thru the leak causing the foaming and related noise. Since the rack replacement (probably 6 years ago) the PS has been 100% silent and works perfectly.