95 dodge Cummins

olgentdc · Mar 16, 2010

Seems like the 306,000 Cummins is losing prime overnite , NOT Sure WHY ???? ..I changed the lift pump some 6 yrs ago , Sure don't want to do that JOB again , ..

MSM · Mar 16, 2010

Depending on your location, road salt will eventually rust the lines. A small rust pit,almost invisible to the naked eye will allow it to lose prime.Look for small wet areas on the fuel lines. Also the clamps on the return line on the injection pump to the frame line loosen up over time. The transfer pump can have an air leak around the plunger, as can any of the quick connects on the fuel lines. I finally replaced all the lines on mine with diesel rated fuel line from the tank to the injection pump,around the same mileage as yours.

Jim in Ma. · Mar 16, 2010

When my 95 did that - it turned out to be the short return line that comes out of the injector pump

Clodbuster · Mar 16, 2010

I have read that those plastic fuel lines can crack and let air in, but not let fuel out. May be time to run new lines.

olgentdc · Mar 16, 2010

Yes, Thats the one !... hopefully i can fix this without too much fuss,, Thanx guys

Anonymous-0 · Mar 18, 2010

Check the return line like the others said. If that is not the problem...on the backside of the injector pump, there is what looks like a banjo fitting for the return line. It has a check valve inside that goes bad. Don't try to fix it...just replace it. When it goes bad the pump looses prime really fast as it gets older.

95 dodge Cummins

olgentdc

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MSM

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Jim in Ma.

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Clodbuster

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olgentdc

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Anonymous-0

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