No Pressure Episode 18

In this episode, GPM instructors/consultants Alan Dellinger and Jack Weeks discuss a hydrostatic drive that is behaving erratically. Submit your questions by phone [phone], email [e-mail] or simply ask in the comments below.

[@morecorners]

Recently purchased 2008 cat287C MTL. At anything less than full throttle it will start to move forward then gradually slow. With full throttle it will move out but if you start uphill it will slow down. I have not performed pressure check. Did dissect the filter after replacing and it had no metal filings or other debris inside. Any suggestions?

[@JackWeeks]

Thank you for your question, Mark! Your problem sounds very similar to the one addressed in the episode. Have you in fact checked the crossports? You seem to be losing flow from SOMEWHERE, and the crossports would be a good place to start. Presumably the fluid isn't leaking onto the ground, or you would have likely mentioned that, so it must be leaking internally going from a higher pressure to a lower pressure (taking the path of least resistance in other words). This could, of course, be any component in the circuit that could develop a path from a pressure line to a return line, but check for bypassing in the control valve, the crossports, the system relief, and the hydraulic motor. Remember that pressure drops that don't do any work generate heat, so look for any component that has a temperature gain. Good luck with your troubleshooting and I hope this helps!