1976 F-150, it came with 2 gas tanks, one long one one in the middle driver side area, and one square one in the way back area. Only the front tank works.

The front one, when I fill up, gas always wants to overflow and leak out, even if the tank is empty. The only way it will fill up is if I put the gas in VERY slowly. It takes forever this way.

Any ideas why this would happen?

 

Vent hose plugged or fill hose constricted, take a peek under the truck. Usually caused by rusted out bed mounts. Others have had the same problem, check old threads.

 

This is a common problem with the 73-76 pickups. With my 73, I always had to hold the pump nozzle half way out and turn it some - even then I could only hold it half way open or it would click off. I made sure all the vents were good and the rubber hoses were good with no help... I ended up switching to a 77-79 box that has the square door (I was doing a full paint job anyway). These have a better angle on the fill tube, so I can now set the nozzle in there on full and no problems.

 

Wow that sounds exactly like my situation, that's how i have to do it.

Darn... is there a way to alter the angle without replacing the whole bed?

 

The other thing I was considering was cutting the door area off a 77-79 and welding it into my 73 bed - or replace the left bedside with a 77-79 bedside. But both are a lot of work and require painting to match. I swapped beds because this bed was in better shape and had the 77-79 doors.

Marty

 

I have the exact same problem with all of 4 of my 1992-1996 F-350s.

It is very irritating.

So next time I get chance to take my bed off, I am going to put in a HUGE one way check valve breather vent on the top of my tank. So air can escape fast but liquid cannot.

 

I have the same problem with my 76 F250 when filling up. I was just looking under my truck last night trying to come up with a solution. I have decided that where the first 90 degree turn is on the filler that I am going to fabricate a piece of sheet stock to fit the throat side of the bend. My intention is to widen out that portion of the filler so that the pump nozzle will be dispersing the gas more directly down the fill rather than straight back against the heel of the elbow which I believe is the source of the problem. If it works I will post a picture or two and show greater detail of what I did.