Fuel filler problems on A100

Hi guys,
I recently filled my gas tank for the first time and took it to my upholsterer to fit a headliner. He called me the next day to say the fuel was spewing out the filler. Now the tank was about 3/4 full, and there is a breather pipe. The sun was hittng the rear end, and warming the bodywork nicely. I have also fitted a 69 Charger flip-cap, so it does not breathe. I wondered if anyone else had similar problem with a tank pressurising like this. Even after venting (popping the cap) a few minutes later it was pushing fuel out the filler neck. I had to drain the tank as much as possible to prevent further fuel loss. I checked my breather tube and noticed the vent tube for this is at the bottom of the filler neck (six o'clock position near the cap) as opposed to the top (12 o'clock position). And there was a small amount of fuel in the breather tubing.

I will post pictures as soon as I can get the truck home. Looking forward to any pearls of wisdom from other owners

must breathe/vented type i do believe on the older models
leave the cap loose till u can replace it.

If the sun is shining on the back of my van for a bit I can smell gas fumes coming out of the tank. I have a locking gas cap but it is loose enough to have about an 1/8th or 1/16th of space between the filler neck and the rubber gasket on the cap (just enough to let pressure out).

My tank has an overflow/vapor vent line that runs off the top of the tank and goes up into the body work where the tank filler line is, I assume it hooks back into the tank filler line up there somewhere. Also, when adding fuel I only fill it until the gauge says full, I don't "top it off" to prevent an overflow like you experienced.

I haven't had mine overflow like yours did though, you definitely need a vented cap and don't make any sparks around it when the sun it out

I have the same problem as welll. From what I've learned is that there is no venting for these, the cap is supposed to be vented which mine is and still l have this problem. I have found that I can only fill it half fulll, anything more and I have a problem with it pissing out the filler neck. As much as I hate it, it's something I have to live with until I can come up with a solution to prevent this from happening.

Something else Id like to add just as food for thought for you guys with the overflow problem.

Like dix mentioned, is there a chance your overflow tubes are collapsed or plugged with something? It should vent vapor out of the top (drivers side) of the tank with a 3/4" rubber hose.