Hyd Fluid Change


New Member
I have a DP on a Freightliner chassis. I change fluids/filters at or below mfg suggestions, particularly oil. Freightliner recommends changing hyd fluid at 24K miles or two years. Since the hyd system is "enclosed" I'm trying to figure the necessity for this change. I do not drive my unit in "severe conitions"-just interstate or similar roads. What do you do and why? Thanks!