gas spilling-different than others

I did a search first and found some gas spillage threads but none like my issue. I filled my Valiant Friday and parked it in the driveway like usual. Went for dinner in the wifes van and when we got home I noticed a puddle under the Valiant. As I walked around the car the gas was spilling out of the fill tube.
This is confusing me because if it was overfull it wouldve spilled out on the drive home wouldnt it? How could it make it home without a drop and then sit for an hour and spew out just sitting there in the driveway? Personaly I think the damn things possessed

Gas can expand due to temp. changes

One thing to consider is your vent is clogged and it builds pressure in the heat and pushes out the easiest path.Or the drive home splashed the gas over a piont where it holds the gas and seeps out.What ever it is thats odd for sure.Good luck.

Couple of things.

1 When filling, the car may have been in such an attitude such as slightly up/ down hill, or just slightly tilted sideways, to place the filler in a "more up" position, allowing more fuel in

2 Your home parking may be OPPOSITE, IE a tilted attitude with the filler slightly down

3 If this was a station with underground tanks, the fuel is nice and cool. If this was a warm day, and you got the tank "nice and full" the fuel expanded and forced it's way out

4 Some pumps are IRRITATINGLY slow, others are ABUSIVELY over--pressure, and this can dramatically change the way the tank fills

I'm not familiar with venting on the earlier cars. My 67 uses a sealed, unvented cap. The vent for my car is a small tube welded into the filler neck way up high where the filler comes out of the side of the car. This tube goes UP a few more inches to the top of the trunk, then turns down, through the trunk floor, and ends inside the rear frame rail.

So a 67 can do this same thing, except the cap doesn't normally leak, but it CAN puke fuel out the vent if over--filled

I see we were all typing at the same time!!

Also if the tank was very warm from fuel or just road heat and the tank was filled to the top as it cools down the tank would contract and force the fuel out.A lot of sernerios about heat expansion.

Fuel is expanded and contracted by temp. change. Where I work if a driver fills in the cool morning and the unit sits till the afternoon before being used again it will spill out the vent hose. Because of this the drivers are told to fill during the warm afternoon or do not fill it to the top in the morning right before parking it.

Temperature expansion could cause it to overflow but it would have to be really full to do it in that short amount of time. A gallon of gas will expand 4.8 cubic inches when going from 60 degrees to 90 degrees. You multiply that times the number of gallons and ....oops! Dennis

Still going with possessed:twisted: Jk. I was thinking it was do to expansion but didnt think it would expand that much. It was full but not over full. Learned that lesson already.

As mentioned, check that your vent is open. In my 65 Dart, similar to 67Dart273's, there is a small stub tube in the side of the filler tube that a thin tube (~1/16"D) attaches to via a rubber hose. It snakes up high, then back down thru the black rubber floor gasket of the filler tube (instead of frame rail). The tube's exit is often plugged from undercoating or road debris. Try blowing thru it from the top.