Gas Cap Question?

[jdfarmer]

I bought a new gas cap about ten years ago because the old one was loose and leaked a lot of fuel. The new one was loose and leaked a lot of fuel also. Looking at the top of the filler neck I thought it looked a little pulled out. So I tapped it with a hammer in a few places and the cap seemed to tighten up better. Little being good, so more must be better, I tapped it several more times around the neck while test fitting the cap, now it doesn't leak and is tight. Just a suggestion.
I am not an authorized fuel tank technician, proceed at own risk. Your mileage may vary. etc. etc. etc.