I have a 1988 Case 760 trencher that runs atf. It is expensive to replace. Can I dump hydraulic oil in it and over time it will eventually run only regular hydraulic oil? It has a lot of leaks and they are expensive to fix vs amount of time I use it.
Um... I think changing the oil and the UOA's are out of the question. This is an older piece of equipment that is leaking ATF to the point the OP'er is asking about using cheaper hydraulic fluid instead... since fixing the leaks is cost prohibitive.
I'm no expert on hydraulic systems, but the viscosities of an 80's ATF and hydraulic fluid are a wash. I'm wondering why CASE would spec ATF, or if that's just what's always been used?
If atf is specd then use atf, or sell the thing. But using traditional hydraulic fluid in it's place without some 'before' testing so you have something to compare the 'after' testing to would still be the better option.
How much is the cost to repair the leaks vs the cumulative cost of tons of ATF and time?