View Full Version : Toto GMAX TSU18A - Water won't stop
02-05-2010, 07:50 PM
One night, our Toto Toilet just kept running. I have a GMAX TSU18A in my tank. After reading the forums here it seemed to indicate that this model is not fixable and to buy a new one. After installing the new TSU18A, the same problem. The water won't stop. I have tried adjusting the height from the water line. According to instructions it needs to be within 1/4" from the overflow height. I've tried making it way below, or slightly above just to see what happens, and still the water will continue to run. Any ideas?
02-05-2010, 08:27 PM
Shut the water off, let it sit for awhile, and see if the level drops. It is usually the flapper valve that is leaking, and the fill valve is just doing what it should...trying to keep the tank full.
02-07-2010, 06:50 AM
I figured it out. It wasn't a leaky flapper. This type of fill valve has a blue cap on it. Somehow I had seated the cap down too tight. This was actually pushing on a plastic piece which kept the valve open. When I reseated the blue cap on less tightly the valve worked just fine. Thank you for your reply!