My owner's manual says to use Type F ATF for the power steering. Back in the late 1950s, when my dad got a car with power steering (1955 Chrysler New Yorker), I learned that the correct fluid to use was ATF. Over the years I saw that some manufacturers specified their own PS fluid and generic PS fluid was sold in parts stores, but I've always used Type A (GM) ATF (Dexron in its various iterations over the years up to III, after which it becomes weird). Type F ATF isn't very common anymore since Ford stopped specifying it and it's harder to find
and now more expensive that Type A (Dexron). Apparently the difference is in the friction properties and I've heard that if you use Type F in place of Dexron in an automatic transmission, it gives firmer shifts. Anyway, what's the concensus on what to use in a 740 and why? I just saw Dexron mentioned in the FAQ.

The reason I'm asking is that when I started the car yesterday morning, the pump was making a moaning sound and the steering was lumpy. I checked the reservoir while it was running and it looked like it was sucking air and cavitating. Not having any Type F handy, I stopped at the parts store and picked up a litre when I got into town and poured in half of it. Just driving around didn't get rid of all the lumpiness, but going from lock to lock a few times after I got home seems to have just about done it. These cars really seem to really act up when the fluid gets low.