What does everyone like to use. I have seen 10/30 or 10/40 motor oil or transdraulic. Draining my system tomorrow to pull the filter in the hydraulic block as I think that is what is causing my forward and back not to work on my early 80s 742 with the ford. Appears I have to tip the cab back to do this. if there are any secrets out ther on this filter let me know and what type and brand hydraulic oil people like