Why Type F for Volvo PS?

[Oldyellr]

I have a 1992 Volvo 740 that specifies Type F ATF for the power steering. I followed that recommendation, but when I replaced the rack with a junkyard one due to rusted out steel lines, I put in Dexron and it works fine. Reading what people post on Brickboard, it seem a lot use Dexron, mostly synthetic, and swear by it.

So my question is, why would Volvo specify Type F instead of Dexron, which most manufacturers do? I know some Fords specify Type F for the PS, but my Volvo is from before Ford owned the brand. All I know about Type F ATF is that it was specified for Ford transmissions years ago, has different friction properties giving firmer shifts and perhaps has more atnti-foaming agents. I'm not asking for other fluid recommendations, just wondering why Volvo would have specified it.

 

[Eddie]

Volvo & Ford were married for many years and possibly Ford wanted to be able to use Ford fluids so they changed seal materials. Maybe the PS pump is a Ford pump? Ed

 

[ragtoplvr]

Type F and Dexron differ mostly in friction modifiers, dexron has them, F does not. Old trick is to use type F in GM and get firmer shifts. Ford used different friction material than GM Power steering does not have clutches, so either would work. Try to avoid Dex 6. Unknown how that might act.

Rod

 

[Whimsey]

My 1996 Ford Contour uses Type F ATF in it's rack and pinion power steering. That's what I've been using and so far all is well. It's inexpensive and works well in this car. What works well I don't change.

Whimsey

 

[artificialist]

In power steering systems, I often replaced the Type-F with Mercon, Mercon V, Mopar ATF+4, and Dexron VI, and never had a single problem.

Since power steering systems don't have wet clutches, friction modifiers don't matter much.

 

[ryanschillinger]

I'm running max life atf red cap in the ps system on my 67 Ford F-250 which specs type f. It works great. Flushed with new pump install and all is well.

 

[Lubener]

You don't need friction modifiers in a power steering system

 

[eljefino]

Noone answered the question!

I would assume Volvo figured Type F was universally available... remember, this was 1992, and Ford used Type F in trannies until 1985 or so and in PS systems through 1992 and beyond.

Volvo didn't use Ford pumps though, they don't have that nasal whine.

To me it doesn't make sense, they have to put 2 gallons of dexron in their Aisin Warner trannies then a quart of type F in the PS system at the factory, if they were even following their own advice.

The cardone reman rack for my 940 came with an admonishment to only use PS fluid and not ATF, but, what do they know, it leaked from a hard line flare fitting right out of the box.

 

[Lubener]

I stopped wondering why. I use what is specified and move on to more important things.