Leaking fuel..

[81_Chevy]

so, it started when i was at a softball game. some guy came over to me and said my truck was leaking fuel and sure enough it was. out of the passenger side tank. i was also parked on the side of the road with my pass side of the truck down of the angle of the road.

but heres the problem, my pass tank has had a huge hole in it for over 10+ years, so ive never filled it up. i just filled my driver tank up right before the game so it was full. so how is there fuel coming out of the inside of the pass tank when theres no gas in it? it was leaking from the inside..

the tank selector valve has never been touched since its tucked away inside my dash so nobody does touch it. so its set to the drivers side tank. im really confused on how this is happening. theres only signs of wetness around the hole and at the front of the pass tank.

i pulled the truck to level ground and it stopped leaking, but after driving around town for a while its still leaking (not like the steady stream is was before) little drips here and there. is there a back feed line between the two tanks?

and advice is appreciated!

-Nic

[Irish_Alley]

not sure about ours. but i know a buddy of mine has a 94 f150 with dual tanks. had a running rich problem with fuel from one side so we just flipped the switch and fixed the problem. just ignored the problem. well after a while he would still be getting problems and swore his wife was filling up the wrong side. one day me and him went for a test drive after i repaired his brake line. had black smoke rolling out the tail pipe. got him to pull over i went to the drivers side tank (didnt use due to it being broke) unscrewed the cap and fuel pored out. put the cap back on and switch to drivers side no problem running the truck. after research the vuel tank selector valve which ford recalled was sticking on the return side and was putting returned fuel into the drivers side even tho it was pulling from passengers side. imo i would be thinking this for yours but i would wait till we see what everyone else thinks

[Low87]

That was my first thought (return fuel going to the wrong tank).

[Boone83K10]

the tank selector valve has never been touched since its tucked away inside my dash

why is your selector valve under your dash? It should be under the truck, inside the frame rail on the passenger side between your bed and cab.

[bd]

First off - check the condition of all your fuel lines!

With the left tank topped off, at precisely the right chassis angle, fuel "could" siphon through the vent line into the opposite tank.  But, that should be a rare occurrence unless - the vapor canister line was capped, because the canister was removed.  Another possibility is with a 6-port selector valve; stuck in a partially committed position, return fuel from the fuel pump can transfer to the wrong tank.

[81_Chevy]

I ment the switch for the selector valve.. Sorry my bad lol

I'm guessing that the return is stuck on the wrong tank like you guys said.

I'm going out to the black hills for a week tomorrow so when we get back ill look at it. My dad said he was planning to pull the dual tank system out anyway and just hard line the one tank, since we don't use the other tank anyway.

Thanks for your help! I will post back results later!

-nic