Thanks for the info! Once I knew this was the case, I knew it was REALLY suck and that only a torch would unstick it (which I didn't have). So, I cheated and may pay the price down the line. That tube was bendable enough that I bent it up, unscrewed, put on the new one, and bent it back down...Worse comes to worse it fails and I buy a new one, which wouldn't be terrible since it was such a rusted piece of junk.
Anyway, thanks for this info, it helped me just 'go for it' to get the job done since I knew the issue.