My mind must be feeble because I can’t find this info anywhere searching here or the interwebs at large. I have a new to me 85 F600 with a 370. Does the power steering pump take dex/merc or Type F? Correct me if I’m wrong, but the hydro-max pump takes dex/merc.

 

Ford stopped using Type F in transmissions around '77.

It kinda doesn't matter which you use in PS, because the big difference was that Type F lacked friction modifiers for soft shifts. PS doesn't care about that.

That said, IDK what was originally spec'd for your '85 F600's PS. I run Amsoil's PS in mine , and the last guy ran Lubrizol I believe; at least, that's the can I found behind the seat.

 

Thank you sir! Small world, I was in Oak Harbor last weekend picking the 85 up. The story is that it’s a former City of Oak Harbor truck even.

I’m going to try dex/merc II. It has ATF of some sort in it now and isn’t complaining about it. 🤞

FWIW, the PS in my 89 F350 calls for Type F in the PS. But when I replaced the steering gear with a Redhead unit, it came pretested using dex/merc. I think you’re right that they’re fairly fluid agnostic.

I’m in the slow descent of analysis paralysis. lol

 

That has to be pretty much the last year, but yeah, Ford kept up with the "Type F in PS" labeling into the 80s.

PS lubricant (except antique Citroen) needs a lot of the same properties as ATF: really good anti-foaming, low viscosity, high heat durability. Anti-friction? Not so much, because other than rack stiction (and that's not really a thing you're going to feel with PS; more of a motocycle-front-forks thing), friction modifiers just aren't needed.

You can even mix different types in the PS system, and it won't be detrimental (IMO). I am more about clean, than type. Brown PS fluid is pretty much always bad at my house.

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Yeah, we're pretty much neighbors