i filled up the tank on the Fridge, parked it in the garage, came back later, and gas was expanding up the filler tube and running down the side of the truck......any help solving this problem?
Thanks!!

 

vent it. After market cap on it now like a locking one or something off of something else you had? Hot envirement like warm garage or sun light and gas expands. Have you had this problem before or has something changed to your gas tank or cap? Mark

 

You just can't fill it so full when it is hot out! It is pretty scary to come out and find your truck covered with gas isn't it? I have had the pleasure.

 

Mark, the cap was on the truck when i got it...it's a locking cap...i assumed it was a "stock replacement", but i don't know for sure. I haven't had this happen since i had the tank cleaned, baffle and return line installed (for the fuel injection), so i don't know if it'll do it again; so, getting a "vent" cap would solve this? I'd really like to keep a lock cap on it......; i remember (in days gone by) syphoning gas..don't want that to happen to the fridge..... ...spurredon...yea, VERY scary......
thanks guys!!....really appreciate your thoughts! scott

 

Buy non-expandium gasoline. It is hard to find. This particular gas violate the laws of physics and does not expand when it's temperature is increased.

Obviously I am kidding, you just can't fill the tank quite so full in the summer time.

 

It can be a problem anytime but worse in the summer. I never top the tank off and never park on an angle with the drivers side lower. Just get used to listening when you fill and you can hear when it's getting full, stop before the pump shuts off. Those caps have to be vented both ways because there is no other vent on the tank.

 

A vent won't solve the problem of overfilling. There is very little area between the top of the tank and the top of the fill neck. If you run gas up into the neck (often where the gas pump trips off), it is bound to come out when it expands.

Doing a little digging around on the net shows that gasoline expands at a rate of 0.069% per degree Farhenheit. If you pump gas out of an under ground tank that is only 60 degrees and put it into a tank that is setting in 95 degrees, it will expand roughly 2.4 percent. So if you fill your standard 18 gallon tank on a day like this it becomes a little more than 18.4 gallons. I don't think the fill neck will hold much more than a quart so there you go! Prolly all my math is wrong but we all know that it expands and runs out if you get it too full so something must be happening somewhere!

 

If the locking gas cap wasn't vented, you would have known this the second it was removed. Using a non vented cap causes pressure build up, so there would have been a loud whooshing sound when removed.

Using a non vented cap on these trucks not only causes pressure build up, but could also cause the tank to partially collapse.

 

The O.P. stated that he is running fuel injection. A.F.A.I.K he should be using a non vented cap to keep the proper pressure for the fuel injection and the return line back to the tank would keep the tank from collapsing.

 

That's just about what I was gonna say. Thanks.

 

The tank needs to vented somehow, to replace the volume of fuel used by the engine process. New systems use charcoal canisters and purge valves.
Just a random thought. Carry on.

 

thanks for all the feedback guys....great points.. the cap is "loose" so it's vented...sounds like the easiest thing to do is just not fill it rather than adding a charcoal canister and purge valve, if that's an option with the fuel injection. will that work?

 

Hobbs the charcoal can and purge valve are more an environmental thing, dealing with the fumes while allowing the tank to breath. As Spur (and others) pointed out I think your spill issue can be resolved by not topping the tank off before storing the truck.

 

While proper venting is a must, tank pressure isn't required for the fuel injection to function. If you are using the original tank your options are few. You must use the cap that is vented both ways and those are kind of hard to come by in the parts stores. And you just can not top off the tank. Your best bet would be to get rid of that tank and put one between the frame rails in the rear. Do some measuring and hit the junkyards. A tank from a Jeep might fit good. I had one from a suburban that fit between the frame rails on my 69 but the Chevy fuel gauge runs on a different ohm range than a Ford so you have to deal with that. Another option is to measure what size you need and have a sheet metal shop brake the metal so it only takes 2 pieces to make a tank. Then anyone who is a decent welder can tig or mig the tank together.