I have a Komatsu d31px-21 serial number 50077. The dozer will not go forward or backwards but the blade functions operate as they should and I’m not sure where to check pressure for forward and backwards pump
Do you have any action codes showing up on monitor... L01, L02, L03, L04? If so push the "F" key under the exclamation mark, likely F5. This should jump you to the Current Abnormality screen which will list the active the active fault codes that are driving the action codes.
I don’t have any codes or buttons to push on my dash
John, No codes, must mean issue is mechanical or hydraulic. Please see attached troubleshooting from service manual.
My memory is fading on the stuff I worked on in the early nineties but I seem to recall a pressure check plug on the pump itself. Pull some deck plates and sheet metal and then follow hoses from the transmission back to the pump to identify which one it is.
Ok I think we narrowed it down I ain’t getting any fire to the 1-3 solenoids with lever up but there’s a plug underneath the floor board that isn’t plugged into anything that gets fire when you pull lever up. If you jump that plug the 1-3 solenoids get power I guess it’s the parking brake release but can’t figure out where it plugs into
I just replaced the hystat pump in mine.