1989 F150 leaking fuel from the filler tube. Dual tanks but only leaks from front tank. Seems to leak less when using the front tank, but still runs down side of box. Otherwise starts and runs perfect. Any suggestions?

 

Replace the filler tube, maybe? This is fairly common on vehicles over 10 years old.

 

I seem to remember something about those years of trucks having a problem with the equalization between the tanks. It was also a recall if I remember correctly. A coworker had a 89 or 90 dual tank truck, and I remember him showing me the letter. It's possible the recall was never performed on your truck. Take it to a dealer and ask them about it. Let us know how it comes out!,,,,98

This was several years ago, when his truck was only a few years old.....

 

i had the same problem with my 89 f150. it only did it when the front tank was full and i was trying to use the rear tank. apparently the switch would not close all the way. if i used the rear tank when the front was empty, then switched to the front when the rear was empty, suddenly i had about half a tank of gas in the front again. freaked me out at first, but i got used to using the front tank first, then the rear.