I have a 1994 2500 4x4. Truck looses prime after being parked for a few hours or overnight. I have to crack the fitting for the returnline on the injector pump and prime it manually with about 40 primer pushes. Tighten up the nut and crank it over with the peddle to the metal it fires up smokes like hell then goes. If I shut it down and fire it warm no problem. Today after filling up I noticed a leak of diesel down the drivers side and looks to be coming from behind the fuel filter. Cummins Tech support said it sounded like a fuel return line. Anyone ever had this???????????? I am tired of starting this thing up like a model a :'(

 

Common problem theres a hose behind the filter that cracks and starts to leak....its a bear to change (tight clearances) if I remember right its 3/8" hose....if you change it get the best diesel grade fuel hose you can find because you only what to do it once :-[

 

The supply line is 3/8" and the return line is 5/16" Use J30R7 or J30R9 fuel hose ..... the return line is the one that typically goes bad ..... but while you're in there .... change them both