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Fluidmaster Fix It Zone


Water Leaking From Multiple Areas of Toilet

Whether you have leaking at the bolts, the flush valve, fill valve, or the tank to bowl gasket, the process for stopping the leak is pretty much the same.

  1. If the leak is at the bolts:
    1. Make certain that there are no metal washers in the tank. This will cause a leak. Sometimes just resetting the position of the bolt head and rubber washer will seal that opening.
    2. Tighten down the tank to the bowl so that the tank sits on the ridge of the bowl. On most toilets the porcelain tank rests on the porcelain ridge of the bowl. The needed pressure on the bolt head and washer will seal the tank. Some bowls will not have a ridge, but use rubber washers or inserts to support the tank. Tighten down the tank until the rubber washers or inserts are compressed. Then check for leaks again.

      Note: The nut and metal washer used between the tank and bowl help to hold the bolt straight while you install the tank onto the bowl. Before you install the tank use the nut and washer under the tank to seal. Place the tank on the sink. Add water and watch for leaks. This is an easier way to troubleshoot potential leak problems before putting the tank onto the bowl.

      Caution: Some toilets will not allow the nut and metal washer between the tank and bowl because the space is too narrow. If the hex nut rests on the porcelain, it can crack the bowl. In this case remove the hex nut and washer. Use your best judgment when using these parts.

  2. If there is constant leaking between the tank and bowl, there may be a crack in the porcelain or the flush valve plastic housing. A constant leak means the lock nut is not tight enough or the rubber washer inside the tank has flashing (excess rubber) or fissure-like cracks.
    1. Using a pipe wrench; tighten the lock nut 1/4 turn more, dry and then check for leaking. If the leaking reduces then go 1/4 turn more and check again. If this still does not seal it then do not tighten anymore. Check the parts and gasket for any signs of flashing (excess rubber), or cracks, etc.
    2. If you find flashing, use your fingers to pull it off or use a razor blade to carefully cut away any loose rubber. Make sure you do not cut into the washer.
    3. If the leaking gets worse when you tighten the lock nut, something is cracked. Stop now! and investigate.
  3. If it only leaks when you flush the tank, the problem is at the sponge/rubber gasket.
    1. Leaking may be caused by a tank that is not tightened enough. The tank should rest on the ridge of the bowl for stability -- sealing the tank to the bowl with the sponge/rubber gasket. If you have already tightened the tank down to the bowl STOP! DO NOT TIGHTEN THE BOLTS ANYMORE! Check the fit of the gasket on the flush valve and on the bowl.
    2. The sponge/rubber gasket may not be a compatible type for your toilet. Compare this gasket in relative shape and size to the gasket you took out. If they are similar (or the same) proceed further. If not, you may need to purchase the correct gasket to finish the job.
  4. If there is leaking at the lock nut of the fill valve:
    1. The washer in the tank may not be positioned correctly. The flat surface of the shank washer should be facing up and set against the flanged section of the fill valve.
    2. The lock nut is too loose: Turn the lock nut ¼ turn more. Dry and check for leaking. If this reduces the leak then go ¼ turn more, dry and check for leaking.
    3. Try using a little dab of silicone sealant under the shank washer inside the tank. Sometimes the hole has a chip or is out of round.
    4. The threaded shank is cracked. This would be confirmed by the fact that each time you tighten the lock nut the leak gets worse. Even if you install a new shank washer it will still leak. In this case replace the fill valve.
  5. Leak at the coupling nut: Is the coupling nut touching the lock nut? If yes, the tank may be thicker than most. There are two immediate solutions without replacing the water supply or the fill valve.
    1. Use a flat file on the top of the coupling nut. File 1/8” off of the nut. Then install.
    2. If the coupling nut is not a part of a stainless steel or vinyl connector, you can place one or two stainless steel metal washers under the cone washer and then install.
  6. When you are using metal-flanged tubing as your water supply, you must ask yourself "Is this supply tubing new?"
    1. New tubing may only need a little more tightening. Used tubing should be replaced. There is a flat washer attached to the metal-flanged tubing that is used as a seal between the fill valve and flanged tubing. Because it keeps the impression of the previous fill valve, it may not match up to the new valve and ultimately leak. In this case, install a new spiral tubing washer or a completely new water supply line.
    2. If you hand tighten the coupling nut but your hand strength is not what it use to be, or the position of the toilet makes it difficult to get a good grip on the lock nut, use a wrench and turn the coupling nut ¼ turn beyond hand tightening. Dry it and check for leaking. If this reduces the leak then go ¼ turn more and check it. Do not go any further if this does not seal that connection. Check the installation again as well as the parts being used.
  7. Are you using a metal spiral tubing type water supply? If so, DO NOT use the cone washer from our kit.
    1. Metal spiral tubing requires a cone washer that is specifically made for spiral tubing. DO NOT use the Fluidmaster cone washer that came in this kit. It will not seal the metal spiral tubing. If the existing spiral tubing washer is in good condition you may want to try it. If not, purchase a NEW spiral tubing cone washer at your local hardware store.

      Note: Any tubing that extends up into the tank will not allow the fill valve to seat properly. You will need to cut down the tubing so it can be inserted ½“ into the bottom of the fill valve shank. Use a hacksaw blade or pipe cutter to shorten the tubing to accommodate the new fill valve.