I have owned my Kohler Cimarron toilet for 10 years now and last month (i.e., long after the flush & fill cycle should have been completed) I was hearing a slight sound of running water. With the guidance of Kohler, I was able to identify and subsequently purchase all of the necessary replacement parts to make a total/full repair--replacement of the Kohler silent fill valve, the flush valve, and even the handle. I ordered additional toilet canister replacement seals to have on hand for future use and perfect parts match. Everything is working like new and it was a smart move on my part to stick to OEM Kohler manufactured parts which were the precise application. Kohler's Aquapiston technology is sure an asset to have with these modern low water volume toilets!