Hi guys I have a cat 301.5 (3YW03131) with final drive issues, if i am working in mud it will stop the motors to the point where both motors will not respond to the levers and i have to drag myself about with the bucket until it comes back to life. sometimes when using the machine on clean ground one motor will stop driving but will free wheel when lever pushed moving the driving motor back and forth seems to get it back on line again. can anyone help me with this ? also has anyone got hydraulic schematic for the machine i have 2 i got from someone selling a workshop manual and I'm not convinced there correct.
I'd bet 4 to 1 you need to reseal the swivel joint in the center of the machine. Sounds like tired seals between the circuits bypassing. Sometimes a bit of a pressure spike will cause the old seals to jam themselves into place to seal temporarily. After checking that I would look at port relief valves for the travel spools in the valve stack if it still doesn't perform well. Or I may be all wet, YMMV.
Thanks Lantraxo I will start with the swivel joint and see what horrors i find in there, I have a bit off a engineering background but my understanding of hydraulics is limited to the point i think its all black magic....