We purchased a Champion Elongated Toilet in Dec 2004. It has started the " running" I have seen posted.
I found all your comments and was very concerned. I called American Standard gave them the model number and they are sending replacement parts. They said there is a 10 year warranty and if I have any
further problem to call and give them the reference number and there is a file and any other problems within the warranty they would resolve.
Maybe if you haven't called American Standard 1-800-442-1902......you might try if you still have warranty on your purchase.