DarrylMueller

Thanks I just want the right place.

I took a picture of the area. Is the hex plug were the drain back valve is?

Wow, Thanks for the come back, that is what I was looking for.

This problem is a leak down of fuel when parked or not running. This truck usually starts right away. The last time I used it I did have some issue that it turned over a few extra times when I turn it off. So this is something I was expecting. I have let it set several months and it will not start, so I am sure there is air in the fuel system. I am sure that I could get it going with starting fluid but I would like to fix it. There must be a "check valve" or something like that stuck open and it is allowing the fuel to drain back to the tank. Yes it's an old truck 1976 but in great shape and I have owned it for most of its life. Hoping there is a veteran Mack mechanic that can help solve the problem.