I'm tired of the fuel pump issues of transferring fuel between tanks. Believe me when I say I have tried almost everything possible to repair, to include bed off 3 times, 2 new front fuel pumps and 1 new rear pump, new fuel filter, new (additional) ground wires to pumps, voltage checks at various waypoints in the 12v. wiring system to the pumps, pressure test that are incredibly perfect. Now if someone can tell me what the inside diameter of the fuel return lines is, I'm gonna install a pair of Normally Open solenoid check valves in the lines, each one controlled by the voltage to the opposite pump. Doing it this way so if a solenoid fails it will still run like it does now and not kill the use of that tank. Anyone with the knowledge of the flexible part of the return line size will help me a lot, thanks. my email is somemorebob@yahoo.com
1996 f150 XL Regular Cab 4.9 Dual Tank, looks good, runs good and dependable

 

well I got two 1/4 inch brass normally open solenoid valves, 4
1/4 npt x 5/16 hose barbs, cut the return lines inserted valves, double clamped the hose barbs, and wired the solenoids to the opposite fuel pumps positive wire. initial test are good , just have to take some time/trip to verify if there is transfer. I will post again here.

 

5/16 ?

 

yes, I bought 1/4, 3/8, and 5/16 hose barbs and the 5/16 was it. I have the ford recall check valves installed on the output of the pumps and the normally open solenoid valves on the return lines , and I'm still getting transfer from the back to the front. I can hear the pumps come on and the solenoid click when I turn on the key, or switch tanks. all I can assume now is that the front tank solenoid is faulty and not sealing off the front return line. I have 2 normally closed solenoid valves that I'm gonna put on and wire them to the positive wire of the tank in use. This will cause the tank to be unusable if the solenoid fails. Second thought I may just order another normally open valve, as if the normally closed fails, return fuel will have no place to go and may bust a line or something.

 

just in case anyone ever views this, the normally open solenoid valves did not completely solve the problem. The fuel from the rear tank would still migrate to the forward after shutting off the engine by gravity and or siphon. I changed the solenoid valves out for normally closed valves and it solved the transfer problems. This should be the final post.

 

P.S.

also changed the wiring so that each solenoid valve is powered by the the same pump it is working on.