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Town of Palmer, Massachusetts
The Town of Seven Railroads

How to Fix a Leaking Toilet

Just because your ear does not pick up the sound of flowing water in your toilet or you csn't see water flowing in the bowl, it does not mean you don't have a leaking toilet problem.  Some special detective skills may be called for.

The best trick is to use dye tracing. Take the cover off your toilet tank and put about 20 drops of food coloring inside. If you are already using a blue-tinted, in-tank bowel cleaner, use red food coloring so it won't blend in. Sit back and wait for about a half hour.  If colored water shows up in the bowl, you have a toilet leak.

The trouble spot is almost certainly the flapper-ball/valve seat interface. Turn off the water at the shutoff valve located under the toilet tank and flush the toilet.  Reach in and examine the flapper valve.  Don’t worry; the water in the tank is clean.  In some toilets, instead of a flapper ball on a hinge, you might find a sort inverted mushroom-shaped “valve ball” on the end of a rod.    Whatever type you find, check it for wear and damage.  If it looks beat up, replace it.  Also check the mechanism that supports this valve to see that it is working freely.    If there is a chain, make sure that it is long enough to let the valve close, but that it is not too long so as to loop under the valve and hold it open.  If the valve is on a wire rod, make sure the rod is not bent and hanging up on its guide.

If all these checks pass, the trouble may be with the valve seat. It may be worn, pitted, or crusted with deposits that prevent a good seal. Try cleaning with steel wool or waterproof sandpaper. If the seat is chipped or in very bad shape, you can buy a little kit at the hardware store that sits on top of the old seat and effectively creates a new one. These come with clear instructions. 

If neither the flapper ball or the valve seat are causing the problem the leak is elsewhere. Turn the water back on and let the tank fill. If the water level rises up to the top of the overflow tube and starts trickling down it, the tank-is overfilling. Check the float ball.  If it is the hollow metal type, it may be leaking and becoming water-logged. Unscrew it and replace it with a foam, plastic float ball, available at any hardware store. This type can’t waterlog.  

Flush the toilet and watch the tank fill.  The water should rise up to the water line mark molded into the inside of the tank and then stop at that level.  If it does, good.  If not, the problem is in the ball cock.  The ball cock controls the flow of water into the tank. Flush the toilet again and jiggle the float rod up and down several times. This will shut off the flow of water on and off, and if there are mineral deposits or rust particles in the valve, it might break them free.  If that doesn’t help, you’ll have to replace the ball cock mechanism.  You can get a new one at any hardware store and it will come with good, clear instructions that will make the whole job easier than you think it will be.

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