gas tank problems

:screwy:I have a 96 ford 1/2 ton pickup.The problem is I have duel gas tanks/ the back tank works and the front don't, Now here's the thing. When I run the truck the back tank is filling up the front tank to where it is pouring gas out the gas cap. Can any one help and let me know what it might be wrong.:banghead:

I owned one of these things some years ago. There is a fuel diverter valve near the tanks. Esssentially it switches the fuel flow from one tank to another when you flip the dashboard switch.

Given your tanks have fuel pumps in the tanks themselves, I think your diverter valve is stuck. Instead of isolating the front tank, it it allowing fuel to 'back up' from the valve and fill up the front tank.

Try changing the valve. Also, a new valve may get your front tank working again.

Thank you for the reply.I look for the valve but cann't find it.is it on top of the front tank or under the hood some where?I looked on the frame and didn't see anything the gas lines go in to.:banghead:

The tank select valve is a passive device and operates under pressure from the tank fuel pump in most of these models.
there is a safety recall on some.
If yours is included in this recall Ford will replace for free.
Check for recalls then if you have to replace it yourself
look on the inside of the frame under the driver side for a black
unit about 4 or 5 in. tall with 6 fuel lines connected with the
Ford type connectors used on fuel filters etc,

:banghead: thanh you PVAWTER. i looked on the frame and no vaule.i'm going to take it to a garage and let them fix it and again thank you

Ford had a recall on this concern. They install new valves inline by the fuel pumps. I believe this recall has no exp. Date or millage cut off. The problem is when the remove the tank straps the tanks could leak due to corrision. Ford will not replace tanks under warranty.
( 7 year ford mechanic )