Chevron makes a fluid called THF 1000 that i had looked up to make sure I was using the correct fluid when I bought my 1755.It meet and exceeds all the type 55 hydro fulid specs. Since I don't live close to any dealers It was the best thing I could find. The Chevron dealer told me special fuild has to be used when you have hydralic pump and braking systems on the same oil for high pressure.  I have only used it in the field for about 10 hrs. and so far It is doing fine. It has a deep red color to it.