Re: New Gas Tank Issue

Posted by Don Shields On 2016/4/16 0:09:08

My '54 has the original tank without the dimple. It also leaks gas from the top of the filler if I fill the tank and do not drive it for 10 miles or more after the fill-up. I believe it is due to the expansion of the gasoline in the tank due to the warmer temperature of the tank versus the cooler temperature of the gas station's underground storage tank. I have filled it and made sure that there was no visible gasoline as far down the filler pipe as can be seen at the station, drove it home just over a mile and within 20 minutes gas will start to drip because it has backed up inside the filler pipe. I've been able to stop the drip by jacking the left side of the car up, raising the level of the filler pipe. I've even heard the tank "burp" some air that must have been trapped at the top of the tank when jacking it up, but it still would drip if I lowered the car.

Based on my experience, I wouldn't bother trying to fill in the dimple. I think it's there to allow an exit for the expanding gasoline that will cause it to drip down the outside of the filler pipe to the ground. Mine can drip out in such a way that it gets outside the filler door and drips down the outside of the quarter panel, making a mess and leaving a stain when it dries. Driving the car for at least 10 miles after a fill-up or not filling the tank completely are ways to prevent the dripping.