Correct ATF fluid?

The latest Mercon available is my guess. Dexron was originally developed by GM in the early 50’s. Ford and Chrysler both bought it from them. Later Ford developed their own brand, Mercon. I’m sure either one will work. It’s only PS not a transmission. Lucas makes a PS fluid, and there’s plenty of universal PS fluids available. They all will probably work. They’re all hydraulic fluid. Good thin ATF will work best, any brand, especially in colder temperatures. More prone to minor leakage though if seals are old. If you can see any trace of what was used, might help. Though someone may have used something different than original. Typically Dexron is red, Mercon is blue. Since it’s a Ford, I’d go with Mercon. Usually the newer blends supersede the older ones. My old cars require Dexron 2, Dexron 5 or any Dexron made between 2 and 5 works. I prefer the older stuff if I can find it, because it’s a lot cheaper. So, cheapest Mercon (type) available, any brand, should be good.

 

PS is very forgiving and tolerant to different types of fluids. Back then, I remember seeing good ol' Dexron 3 in lots of Fords. Internationals came filled with regular 15W40 right from the factory. Both had same gears and pumps. Today it is usually just a good quality name brand of power steering fluid. I would try to stick with whatever is currently already in the system. If it is dry, then it really honestly doesn't matter.

 

It really doesn’t matter what atf you stick in it. All of it will work. So buy a cheap quart and roll on