At the first IH dealership I worked at (mid '70s) we had a customer that had a trucking company and owned a USAC sprint car. One day Virgil came in and was griping about this high priced fluid he had to buy to use in the power steering system which was new at the time to sprint cars. Virgil said the main reason they gave for having to use only this special fluid was it's superior anti foaming quality. Phil (the owner) told Virgil that Hy-Tran had excellent anti foaming characteristics and asked Virgil to bring some of the fluid next time he came in. The next time Virgil came in he had the fluid with him. We poured some out, smelled it, compared colors and sure enough, it was Hy-Tran packaged in quarts and priced at a level that would have people today griping about the outrageous cost. I had a 1981 Granada that leaked steering fluid out the ends of the rack and pinion unit until I started saving old Hy Tran to use in it. After a about a month of Hy Tran the leakage stopped due to the seal swelling additives in Hy Tran. As mentioned already, power steering fluid isn't tractor hydraulic oil, but tractor hydraulic oil can be power steering fluid. | 
Is power steering fluid same as tractor hydraulic oil?
