Cummins 4bt

[mike_belben]

Would that be Rick Shaw. I will p.m. you. Always good to have some backup once and awhile. Thanks.

Ive met him a few times at RCS diesel. 
The P-pump fuel system with mechanical lift pump is prone to crack the spring inside the lift pump, and on dodges anyway, to have the L shaped hose between xfer pump and fuel heater delaminate at the elbow and close off.  Very hard to diagnose.  The fuel heater bowls also overheat and melt the plastic at the plug just enough for a suction only leak.  Overflow valve is on the back front end of the pump in a banjo fitting where the return line exits pump body.  Its just a ball and spring that keeps the injection pump galley pressurized.