why is my back fuel tank flowing in the front tank

It is a overflow line going to it.

my 1995 f-250 is pushing fuel from the front tank into the rear tank, so much so that it's overpressurized and busted the seam twice. could this be the same problem with an overflow line and do you know how to fix thus problem?

If it is pushing with that much pressure,you should have the evap system checked,it may be stoped up.all it is is a canaster and 2 plastick lines.that is most likely the problem.

there are no in-line cuttoffs on this system. I removed my rear tank and was going to just run it on the front but when I tried to start it the fuel pumped all over my shop floor! Turns out that the cuttoffs are in the fuel pumps and the quickconnects don't stop the fuel when you dissconnect them! Would be just great if you were going down the road and actually ripped off one of your tanks! The fuel will keep on pumping out of the other one if you are using it at the time feeding fuel to the fire all the way to the explosion!! [:-]

have same problem and have read many post on this subject and have tried many suggestions but so far none that has resolved my l994 F150 from gas going to the back tank. there is no cut off in my system. cpo

I have a 1989 F250 7.3 diesel. my rear fuel tank has been pressurizing and fuel is running out on the ground while driving. when you remove the fuel cap the fuel level is right there at the top of the filler cap.