what fluid for Saginaw TC pump w/ pre 97 steering gear

[stamina]

i have a 1990 ranger that i have gotten an adapter kit and saginaw power steering pump for, it’s almost installed but i have a stinging question, what fluid to use? everything w/ a steering gear by ford uses Type F atf, the saginaw pump from the 04’ liberty calls for just ATF (mercon or whatever) as it is a rack and pinion setup which fluid do you think i should use?

 

[franklin2]

I use power steering fluid from the parts store. Even with the old Ford pumps, seems to work fine. The pump in my Bronco doesn't even have that classic loud Ford pump whine they usually have.

 

[4.0blue98]

You can use either ATF or PS fluid as long as you don't mix them. I've had a couple Liberties with that pump (an 02 and an 05). The 02 had PS fluid from the factory and the 05 had ATF+4 (Mopar trans fluid). Same pump in both so Mopar simplified things around 2003. If you mix it will get noisy. The PO of my 02 mixed and it would whine below about 20F even after a flush.

 

[19Walt93]

I'd use Mercon fluid, that's what's in my 77 Mustang and 93 Ranger. If you look at the Ford power steering fluid bottle, it lists the spec on the back. There's ATF in the bottle for about 3 times the price per quart. In 2017, Ford's transfer case fluid sold for about $14 a quart and it met Mercon specs.

 

[stamina]

so throw some valv MaxLife in there and be done with it