There is a dripping noise in my toilet tank. I think the black suction thing does not seal properly. Can this be the source of the noise—and how do I fix it?

The "dripping noise" you hear could come from several sources. It is possible that the tank water is too high; perhaps the flapper (the "black suction thing") does not seal properly; or the ballcock may be worn out and in need of replacement. Before you begin, first determine what type of ballcock is installed in the tank and how it works.

There are two common types of ballcocks, but four ballcock styles and adjustment methods (which will be discussed later on). In general, the first type has a horizontal float rod with a float or ball on the end; the other type has a plastic float that moves up and down the ballcock shaft.

The ballcock controls the amount of water that enters the toilet tank. Ballcocks are adjustable to increase or reduce the amount of water in the tank. Ideally, the tank's water level should be level with the fill line etched into the interior of the tank.

The common float-rod ballcock is easily adjusted. For more water in the tank, bend the float rod up so more water is required to float the ball high enough to reach the cutoff point. For less water, bend the float rod down so the ball reaches its cutoff point earlier with less water. The float rods are easily bent with your hands.

To bend the rod, place the palm of one hand over or under the rod, depending upon the direction you wish to bend it. With the rod cradled in the palm of one hand, use the other hand to bend it at the end with the float. Be careful not to bend the rod sideways. If the float gets too close to the side of the tank, it may stick on the tank.

With age the float rod often becomes loose. If the rod is not securely screwed into the ballcock, the float may contact the side of the tank. If the float hangs up on the tank, the ballcock will not work properly. If the ball sticks in the down position, the water will not shut off. If it sticks in the up position, the water will not turn on.

Vertical ballcocks have not been around as long as float-rod ballcocks, but they are very popular. A big advantage to the vertical ballcock is that the float can't stick to the side of the tank. To control water flow with a vertical ballcock, move the float up and down the shaft of the ballcock by squeezing the thin metal clip on the metal rod next to the float and moving the float up or down. Moving it down produces more water; moving it up produces less. When you reach the desired placement, release the clip and the float will remain in position.

If the flush valve has a flapper, it may need to be adjusted. If the chain between the flapper and the toilet handle is too short, the flapper will not seal the flush hole, which allows water to run out of the tank and into the bowl. As the water level drops, the ballcock refills the tank. This endless cycle wastes a lot of water. If you notice the ballcock turning on at odd times or see water running into the bowl long after a flush, investigate the flapper's seal. Move the chain to the next hole in the handle to improve the seal.

If moving the chain doesn't help, adjust the length of the chain where it connects to the handle. If the chain between the flapper and the handle is too long, the flapper may become entangled in the chain, causing the flapper to be held up which allows water to constantly run down the flush hole. correct this problem by shortening the chain length. The goal is to ensure that the flapper sits firmly on the flush hole.

Tank balls are sometimes used instead of flappers. If you have a tank ball, you also have lift wires and a lift-wire guide. The guide is attached to the refill tube in the toilet tank. The lift rods attach to the ball, run through the guide, and attach to the toilet handle. If the alignment of the tank ball is not set properly, water will leak past it and into the toilet bowl.

If you are having problems with the tank ball, inspect the location of the ball on the flush hole. If it is not properly seated, adjust the lift wires or the guide to gain a satisfactory seal, The guide can usually be turned with your fingers for better alignment. If the lift wires are too short and hold the ball up, bend them to add length.

If these attempts are not successful, you may have to replace the tank ball. Unscrew the ball from the lift rod and replace it with a new ball. If a new ball doesn't do the trick, the flush valve may be pitted or defective. Use emery paper on the brass flush valve to remove pits in the brass. Sand the area where the tank ball sits to smooth out the rough spots and encourage a better seal. The pits are voids that a tank ball cannot seal. They allow water to leak through to the toilet bowl. Unless you are working with an old toilet, the flush valve should not be pitted.

To summarize, there are four ball cock styles currently on the market.

A traditional plunger-valve ballcock controls water flow with a brass plunger attached to the float and ball. To raise the water level, bend the float arm up; to lower it, bend the float arm down slightly.
A diaphragm ballcock is usually made of plastic and has a wide bonnet with a rubber diaphragm. To raise the water level, bend the float arm up; to lower it, bend the float arm down slightly.
A float cup ballcock is also made of plastic and is easy to adjust. To raise the water level, pinch the spring clip on the pull rod and move the float cup upward on the ballcock shank. To lower the water level, move the cup downward.
A floatless ballcock controls water level with a pressure-sensing device. To raise the water level, turn the adjustment screw clockwise, one-half turn at a time; to lower it, turn the screw counterclockwise.

If these adjustments do not solve the problem, then it's time to replace the entire ballcock unit. Parts are readily available in home centers and hardware stores.

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C.R.S., Inc. · Spokane, Washington · USA