I have a John Deere 950 4x4 with a backhoe attachment I have an ongoing problem with the hydrolic filter being clogged with a white googy substance . I have cleaned and changed the filter many times . I have drained and cut the fluid 50 50 with disiel and ran it for 30 min . It runs for 2 hours and clogs up aain . Does anyone know what I can try to fix this? Any help would be appreaciated .HELP