The owners manual does not state what fluid to use. The shop manual for a 56 Imperial states that you use transmission fluid type A. I had read something on the Imperial site on one of the repair areas to us 10w fluid. I will flush out the power steering fluid this weekend and replace it with Dextron 3 Transmission fluid and let you know how it goes. Anthony 1956 Imperial 1990 Imperial Looking for a 1961