I bought some Valvoline Syntech power steering fluid to put in my '95 F150. Then I noticed the spec was not quite the same number as in my owner's manual. I called Valvoline and they said not to use it as it has friction modifiers and would make the bearing run hotter, possibly burn it out, and would be noisy, and that I should use Type-F tranny fluid. (I had already put about 10 oz in and it did make noise for the first block--presumably until it mixed with the old.) Then I went to a couple stores, but could not find the spec fluid. I finally went to the Ford dealer and got Motorcraft brand with the exact same spec number (can says Type F tranny and power steering fluid). The cans are old and dusty like they haven't sold any of this stuff for a long time. The spec for my truck is ESW-M2C33-F. Normally I don't worry about these spec numbers for things like oil or grease, but in this case it seems important. BTW, how much fluid does the system hold in total? Someone on this site once gave a ball park figure and I think it was around 3.5 pints.

 

I always use the Motorcraft stuff, and I just put a new steering box in, I don't remember how much fluid I put in the pump. About 3 pints sounds right.