Hydraulic oil for Super A

I know this has been talked about numerous times but I would like to know what most of you use. My manual calls for SAE 10 w in the hydraulic unit. I can't find none. What would be the closest to it. Would it be wise to drain all of the oil that's in it now and replace it all or could you just add something to it. I know it's been been on here many times but I need it again. Thanks

Hy-Tran or an equivalent hydraulic oil is what is supposed to be used in these IHC hydraulic systems that is currently available. As noted in several other recent threads on this forum the original IH hydraulic systems on the Super A and C tractors called for Touch Control Fluid which was later replaced with Hy-Tran in the late 1950's. Hy-Tran is composed of SAE 10-W oil combined with an extreme pressure lubricity agent as noted by IHC Product Identification Committee Decision No. 299 dated August 11, 1958. A local tractor repairman who is not associated with CaseIH but an independent that knows I have IH and Farmall tractors and use Hy-Tran for my hydraulic fluid told me to use it in everything as it is the best hydraulic fluid available today. Some complain about the cost of Hy-Tran compared to the farm store brands but I have found the small added expense minor and have yet to have any issues with using it in everything except the earlier letter series Farmalls like my H and M tractors where I use the recommended SAE 30-W non-detergent oil. I do not share hydraulic equipment between the two oils to prevent fluid contamination, Hal.

Hy-Tran, ATF, Most any hyd fluid, it is not being used as a rearend lub or in a TA system, so it's only purpose is hyd oil, ATF works good in the cold months