Make sure the tanks is all the way in and twist it around a little. My tanks are very tight going in so maybe you need to twist and press down very hard to get it where it should be. I have filled my one tank 3 times so far and no leaking whats so ever. You might try another tank to see if that fixes it. Don't know but maybe the wick inside the puncture needle has been pushed out for some reason, take the atty out of the cone and see if you can see the wick inside the needle. Hope this helps a little.