changed hydraulic fluid a while back. Tried to save a few bucks and used a off brand fluid and filter. Tractor didn't perform as well. Shuttered at times and fluid seemed to heat up more. Recently I took my backhoe off and put my box blade on. After about 20 minutes the 3 point lift just quit. I had plenty of fluid. After a lot of time trouble shooting I decided to change the fluid and filter using Kubota stuff. Fired it up and everything works perfectly. I'm not sure what the problem was, all I know is it now works. Will stick with the Kubota brand from now on.