I replaced an old worn grommet to stop a mild gas leak a few months ago. Today while filling up at the gas station, it started dumping onto the ground once it neared the top. I looked underneath to see the brand new grommet had split in half! So now while I wait a week for a new one to come in the mail, I'd like to figure out how it split completely apart. Faulty product? Could I have done something wrong installing it?