New guy here with a question! I got an '88 F150 5.8L 351 and my rear tank has an interesting gas leak issue. I can turn it on and drive somewhere no issue, its when I stop. Whenever i stop after driving it, the rear tank dribbles gas, not a huge amount but enough to see and smell and be annoying. Does that have something to do with the pressure inside the tank pushing some has out whenever I stop? Or is there a hole somewhere? Or both? I don't know and that's why I am coming to you guys. Thanks!

 

When does it do it, only when full, half, low, all the time. I suspect you got a lot of questions that have to be answered. You have twin tanks, no matter how much fuel is in rear tank when your using front tank no leaks anywhere, it's only when you switch to the rear tank you get this leak. How am I doing so far? The leak is at the rear tank for sure, drive all day on back tank no problem or is it just that your driving and can't smell the little leak in the return line? I would guess you have a rusted pinhole in the return line going to the sender or at the sender it self, all the way up top were you cant see it. That is all I can think of right know. If you loosen the back bed bolts and pry the bed up by the bumper grab a flashlight and look inside at the top of the tank. Have the truck running and on back tank. Keep us posted

 

Well it does it no matter how full the rear tank is, and I don't use the front tank because the guy before me never used and the fuel sender is broken or something I think cause the gauge doesn't work when i flip the switch, that's another project haha anyways. I will have to try loosening the back bed bolts and pry up the bed by the bumper and check the top. How involved is that going to be? This is my first pick up (hopefully first of many!!) haha. Thanks for the quick reply and great info, I will keep you posted!