CAT D5C bulldozer will run for a time (~30mins) and then stall as if out of fuel. When this happens I've filed the fuel filter (which would be half full) and it'll start up and stay running fine for a bit. Other than playing with fuel filter I just clean the brass cylindrical screen that's apart of the fuel priming system. The priming pump itselfhas been near impossible to use as intended and can barely be pushed up and down to pump fuel. Any help in troubleshooting and diagnosis would be much appreciated. Thanks
Sounds like it might be creating a vacuum in the fuel tank. Is the tank venting properly. Next time it does it take the fuel tank lid off and see if there is air sucking in when you remove it. There is a change up on the caps on some models due to plugging of the vent. It depends on what serial number you have. I have also seen tanks slightly plugged at the shutoff valve coming out of the tank. Take the line off there and make sure you have good gravity flow.
My excavator was doing the same thing.It was the screen at the tank outlet.Take a portable air tank and blow back from the prime pump.It took a couple of try's but mine cleaned out,and got the "rusty crap" in the first filter.Or if you can get to the screen just pull it and look.