How long does hydraulic fluid last?

[mfreund]

Change the filter regularly if it is running cylinders. On my hydrostatic transmission tractor, I have to drain all the oil to clean the sump screen. I just put new in because it is cleaner. Regular recommended is 400 hrs. I went 500 with no problems.

 

[vtsnowedin]

On my gear tractor the recommendation is to change just the filter at 50 hours then go to 1200 hours before changing the oil and filter again. (and clean the screen) Hydro transmissions would probably be more often. I can tell you if you get water leaking into an open center system the oil will look milky. At ten gallons per change doing it more often then called for gets hard on the wallet.

 

[fishheadbob]

My 3930 only gets about 60 hours per year nowadays. The manual says something along the lines of 600 hours. I change both hyd filters ( optional hydraulic pump ) about every 125 hours; between the loss during filter changes, the occasional blown line, and loss from a leaky cylinder here and there I add about 2 gallons a year. The oil looks like the day I bought it and all hyd stuff works fine. Gear transmission.