M715 Fuel Pump

[Gregg Irvin]

My M715 fuel pump is backed up by a secondary in-tank fuel pump (with a dashboard toggle switch). Wether or not original the main fuel pump is inadequate: going up a hill, for example, it is necessary to turn on the in-tank pump in order to get sufficent fuel. The question: How can this be solved? Is there another fuel pump that could be purchased that does the job?

[osut362]

original trucks did not have a secondary fuel pump. likely the original is bad and the p.o. added the electric to avoid rebuilding/replacing the existing pump....al

[Don Cavey]

original trucks did not have a secondary fuel pump. likely the original is bad and the p.o. added the electric to avoid rebuilding/replacing the existing pump....al

That makes sense to me. There are rebuild kits for the pump. But if it is bad, why have it in the circuit? Shouldn't it just be bypassed and use the in-tank or secondary whatever it is only?

[brute4c]

If it were me, one pump and only one...

[97XJSP]

me too... If the pump in the tank works on it's own, I'd just bypass the stock pump, unless you want it 100% original. I believe the recommended pressure is about 3psi. It wouldn't be hard to check that. If you do some searching, you'll find a good number of threads on here which are related to the stock pump as well as 12 and 24 volt electric pumps.

[SVENG52]

I had issues with reliable consistent pressure from my original pump and a new pump from memphis. I run a single electric 24 volt pump externally. Since the change my 230 runs alot better

[rboltz]

I had issues with reliable consistent pressure from my original pump and a new pump from memphis. I run a single electric 24 volt pump externally. Since the change my 230 runs alot better

Same here.