power steering pump problem

Transmission fluid is 20w hydraulic oil. The high temp and detergent additives give it its smell and color. Even the most modern trans fluid couldn't do any harm to a power steering system. Mainly because there is no difference between the materials used in building steering systems and transmissions.
Chrysler did use basic 20w oil, Only because it costs less.
You'll find a lots of mfgrs do the same today for the same reason.
Trans fluid has a heck of a lot more additives today that steering systems still don't need.