Strange Toilet Leak

Water leaks in a toilet should not be complicated, but sometimes disguise or hide themselves in ways that perplex. I just fixed a leak I had never seen in all of my years as a homeowner. The leak was caused by granules of rust that kept the flapper from sealing fully. The rust came from the steel arm which connects the ball float with the fill valve. See later steps for details and photos.

Often the flapper at the bottom of the tank (red/pink round device) deteriorates. The rubber becomes rough and granular. It looks good, but rubbing its underside leaves a dark stain on your finger. Or, the fill valve (white device with four corner screws) does not seal and water constantly runs into the tank, although slowly.

In the case of a flapper leak you may hear no noises punctuated by the sound of the tank topping itself off. Often the house needs to be completely quiet for you to notice. In the case of a fill valve leak you hear a faint sound of water flowing continuously.

Materials

• 1/4 inch aluminum rod

Tools

• Hacksaw
• 1/4 x 20 thread die and die handle tool
• Magnetic grabber

A while after the toilet fill valve has shut off, the porcelain above the water line should be dry and there should be no ripples on the water surface.

What we saw was moist porcelain with faint signs of moving water. There were faint ripples on the surface of the water. See the text boxes on the photo. There are signs of ripples and faint water flow in the photo because the fill valve just shut off. Water is still draining slowly from the rim holes below the toilet seat. But, after a short while the porcelain should be dry above the water line and the water should be still with no ripples.

We replaced the flapper, but the signs of leakage continued.

The bottom of the toilet tank shows a number of different stains and discolorations. Recently, though I noticed shards of something, especially around the flapper. Something made me wonder if it could be rust, perhaps from the bolt heads that hold the tank to the base of the toilet. I worked at removing the rust pieces as best I could. I found I needed to do this more than once.

I moved a magnetic grabber on the bottom of the tank and noticed the shards clung to the magnet. Most of the shards were too large to migrate and disturb the seal between the closed flapper and its base. But, there were probably finer pieces of rust that did lodge under the flapper and disturb the seal. That would cause the very slow leakage we had been noticing.

The photo shows the old steel arm between the ball float and the fill valve. I had overlooked it and never gave it any thought. But, once I noticed it, I could see how diminished the diameter of the arm was. Much of it had rusted away.

I could have replaced the old steel rod with a new steel rod, but wanted something that will not rust. A trip to a store found none of these rods available in that store. I had some 1/4 inch aluminum rod left over from another project. It will not rust. I sawed a piece of the rod to the length of the original steel rod and cut threads on both ends. (I am accustomed to cutting threads on steel. Usually, the die will pull itself farther onto the rod. But, the aluminum is soft. I had to exert a constant downward pressure to keep the die moving forward and not destroying the threads already cut.)

I put my new rod into place. I did need to bend it by hand a little so the float ball did not rub on the side of the tank or catch on the raised flapper, also to set the water fill level. I eventually replaced the rusting bolts on the bottom of the tank with solid brass tank bolts from the local hardware store. (Scale and rust were still coming off of these bolts, and there was still a little leakage showing in the bowl.)