IH Farmall 656 gas/ IH 240 Utility/ 2, Super C Farmalls/ 2, Farmall A's/ Farmall BN/McCormick-Deering OS-6/McCormick-Deering O-4/ '36 Farmall F-12/ 480 Case hoe. '65 Ford 2000 3 cyl., 4 spd. w/3 spd Aux. Trans
I'm pretty sure Case would recommend TCH fluid. But last I checked about a year ago, it was $80.00 per 5 gal. pail.
Personally, I use TSC's premium trans/draulic fluid in my old 480C. Works for me, but use your own judgement.
Last summer I was wondering the same for my Case 580K that was low on fluid. But then the auto parts guy asked me a question that I couldn't answer! 'Is you tractor a shuttle shift? There are two types of hydraulic fluid, one for shuttle shifters and the other for ??? (I forget)"
Turned out that it was a shuttle shifter and I got 5 gallons of Wolfs Head tractor HT fluid and put some in.
That's when my problems started because I hadn't realized that hydraulic fluid is almost colorless and even in the bright sunlight the fluid level window looked empty. I had overfilled and had a heck of a time removing some oil.
You must use a flashlight even in the bright sunlight.
The used hydraulic oil contains water and gas and other impurities, the hydraulic oil filtration machine can solve this problem, make it as new lubricating oil.
Find your local Exxon/Mobil dealer and get the Mobilfluid 424. It is a premium grade tractor/hydraulic fluid that meets or exceeds all of the manufacturers specs.
You can use the search function and find several threads discussing it at length.