Type F vs Type FA Transmission Fluid in Power Steering

After rebuild my PS box, I reinstalled, hooked up lines, tightened belt and filled with type FA ATF, its what I had and I thought it was OK to use in place of type F. HOWEVER, upon hooking up the pitman arm after bleeding without load, the pump acts like the box has hit full stop and squeels and complains. The PS is still working, but not 100%. It seems like I can turn the wheel about 10 degrees and then it complains, then another 10 degrees so forth and so on. I originally thought this was an issue with the box, but I R&R another box with the same results. Next I thought it was the pump had gone bad, but I don't see any reason it should. Could it be that the type FA ATF does not behave the same as type F in a PS environment? I'm going to pick up some type F and flush it to be sure, but wanted to get other's input as well.

According to the napa parts man, type F and FA are the same thing.

My local Napa at the time didn't sell type F but sold type FA. I was weary of buying it and the parts guy read me the specs which was the same as Type F. He did say it wasn't a good seller because of the type FA desigination--caused confusion.

Long story short, I put FA in my c-4 a couple years ago and all is still well. I doubt the FA is the cause of your PS issue.

Should work fine I believe the only differances in types of automatic tranny fluid is some of the additives in them which are for the clutch packs in trannys.
I think you have a pump problem. loose belt? or maybe it just decided to go bad. bleeding can do that as sometimes there was some dirt or debris in the system and now its caught in a seal or something.

It's got air in it still.

try to psc performance sites instructions, bleeding PS underload, worked great for me, my PS pump was completely empty after HB install...