1987 Clark 667 with Cummins 378 motor

I have a leak in the PT pump throttle shaft and I am going to try to replace the shaft and o-ring. If that doesn't work I will have to have the pump rebuilt. I cant figure out how to bring the motor (378 Cummins) to TDC. I'm not sure if there are marks on the front of the block that I am not seeing or if there is another way to find TDC.

The Cummins PT pump is not timed. You can remove and replace it without the engine being on TDC.

I got the pump out just fine but it seems that to replace the leaking o-ring or seal at the throttle stem on the particular pump will require taking the pump apart from the rear instead of just removing the snout as had been mentioned in other research I had done. I talked with one shop in Denver and they said they cannot do it due to the pump having an aneroid. Also talked with a shop in Tennessee that I found online and he said they could not do it either. The pump is a Cummins pump made in England. I'm not sure I can even find the correct rebuild kit for it. Any suggestions you could give would be great.

Can you post some pictures of the pump?

Lisscojan said: I have a leak in the PT pump throttle shaft and I am going to try to replace the shaft and o-ring. If that doesn't work I will have to have the pump rebuilt. I cant figure out how to bring the motor (378 Cummins) to TDC. I'm not sure if there are marks on the front of the block that I am not seeing or if there is another way to find TDC. Click to expand... There should be timing marks on the front damper/crank pulley and a pointer on the timing cover. Clean everything up well and rotate the engine by hand until the marks line up at TDC. If you're not seeing them, you can pull #1 valve cover and watch for both valves closed on the compression stroke as you bring it around. Just make sure you're on #1 compression TDC and not exhaust TDC.

Pictures?

Here are the pictures of the pump. Seems pretty basic. Had the top front cover off to try to access throttle shaft but cannot get to it from there. Stephen, this is a Cummins VT378-C motor. Valve covers cover all valves on one side of the motor instead of each cylinder like on the 5.9s

Can you post a pic of the throttle shaft side? That does not look like an aneroid or AFC pump. If I remember correctly there is a round plate with a small tang on the bottom that the throttle shaft protrudes through. Remove the snap ring that's holding the plate in place and remove the plate you should be able to pull the throttle shaft out. There is a roll pin that goes through the shaft and there is a spacer on both sides of the pin. The roll pin hits the throttle stop screws for full and closed throttle. Make sure and watch which way the shaft goes back in.

Throttle shaft side of pump

Not an AFC pump.

turn the throttle shaft clockwise to the stop and mark the housing so you can get it back in the same place. Remove the lever and then the lock ring where I marked the arrows then remove the round metal plate and see if the shaft will pull out. If it wont then there is a lock ring of some sort holding it in from the inside. I had lots of the early PT pumps apart but I don't remember if they used a lock ring or not.