JTBs '90 F150

I have a 1990 F150 with a straight six and it has dual gas tanks. I can fill the front gas tank and by the end of the week all the gas from the front has been pumped into the rear gas tank. I think there was a recall on this subject but I can't locate the info. Can anyone let me know the fix or direct me to an article with the fix instructions?

Snaggletooth

Think that's the rear check valve. Search the 87-96 section there's multiple threads about it.