Bryan Melville

i have a 1995 ford f150 5.0 with two fuel tanks!! and i be leave the front fuel pump is going so i just run the back one. and i noticed that the front is always getting more fuel in it when i stopped filling it weeks ago. and on the front tank it doesn't have much for power. so do i have to buy the whole fuel pump unit?

Houbezra

sounds like the return line is dumping fuel in the front tank. return lines could be crossed or its normal. I'm sure someone will correct me but my 96 150 had dual tanks and i'm pretty sure the return lines connect before the tanks.

fltdriver

cross filling is a common problem caused by the check valve. New pump will solve that issue. Best to do the tank straps while your there because they will probably need it as well.

Ford 4x4

X2 the check valve is bad in the front tank.

Just call me Sean

iTrader: (1)

Yes, you need the whole fuel pump assembly.

Mista_Breeze

From what I understand, the fuel pump assemblies have a check valve in them that prevents fuel from flowing the wrong way, back into the tank, because they both pressurize the same fuel line. I have the same problem, my engine runs lean off of my front tank so I generally use the back tank. But about a third of the gas from my back tank ends up in the front tank when I finally hit e, so I just run lean until I use all of that up. Rather than trying to replace components of it, you'd be best off to just replace the whole pump assembly, that way the check valve gets replaced as well. And like they said, anytime you lower the tank it would be wise to replace your tank straps. Another suggestion of mine is while the tank is down, cover the holes TIGHTLY and degrease it and either use a rust blocking primer or undercoating on it. It may save you from future woes.

Anybody feel free to correct me if I'm wrong.