Power Steering constant howling noise

[_ryanbledsoe]

So, in my 85' 325 we have a 95' M3 Steering rack in, but we have tried 3 different pumps now. Each pump will howl and make a noisy sound that it honestly so annoying and pretty embarrassing to drive around with, especially at C&C. But i will spend at least 20 min trying to bleed out the system. I am using ATF fluid not power steering, but that still isn't making a difference also sometimes once the car has warmed up, same with the PS the sound will slowly go away but once i turn the car off and then back on the noise comes back. Im starting to think that air is some how getting into the system or something is wrong with the rack itself. Im at a complete loss now.

[jeffnhiscars]

The racks are self bleeding once you turn the wheel lock to lock a couple of times so that's not it. If it's the same problem with 3 diff pumps and the rack is otherwise behaving & not leaking I'd suspect a line (possibly the bypass) is hooked up wrong.