Power steering only works when revved past 4k rpms.

[anarchyx34]

I've had a power steering problem ever since I've had this car. Basically the power steering only works if you rev the engine past 4k rpms. I put in a different (used) pump when I did my engine swap, and it got slightly better. Whereas now it would work sometimes but for only say 15 seconds at a time without revving. I figured I got another bad used pump so I bought a brand new one. Same problem! I'm using ATF but I cant see that causing it not to work. Obviously the next step is the rack but it's not acting like a bad rack. Has anyone ever had this problem before?

[coke]

Mine moans and groans, and I too am using atf. but it only makes a sound or noise when im on tar trying to turn the wheel. On dirt, it works perfectly. I think it may be the kind of cut I put in the line when I put my compression fitting on .. not sure.

[jtanguay]

no problems with belt slippage?  it the pump making any noises?

[Kudagra]

I dont have anyIdea..but..

P/s fluid has anti foaming agents that ATF dosent have. Using ATF on old chebbys and Fords is one thing because all the parts are cast iron or steel but  using ATF in aluminum products could lead to excessive wear. Makes sense to me so I believed it.

Jeep has ATF in it. The Subaru and Jetta will get P/s fluid.