How to Fix a Leaky Toilet Tank

Introduction

Unattended toilet-tank leaks can damage flooring and sub flooring, and in more severe cases even the ceilings and framing below, so avoid procrastination when faced with this problem. If the problem is excessive condensation on the tank, see How to Stop Toilet-Tank Sweating.

By: eHow Home & Garden Editor

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Comments: 2

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Instructions

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Difficulty: Moderately Challenging

Tips & Warnings:

Leaks that appear to come from either the fill valve or the flush valve may actually be passing through hairline tank cracks at those locations. If so, you need to replace the tank or possibly the entire toilet.
When you remove the tank to work on it, place it on a bath mat or similar padding to protect both the flooring and the tank.
When you reinstall the tank, it's helpful to have someone hold it level and plumb as you tighten the bolts.
Leaks that appear to come from either the fill valve or the flush valve may actually be passing through hairline tank cracks at those locations. If so, you need to replace the tank or possibly the entire toilet.
When you remove the tank to work on it, place it on a bath mat or similar padding to protect both the flooring and the tank.
When you reinstall the tank, it's helpful to have someone hold it level and plumb as you tighten the bolts.
Don't overtighten the mounting bolts on the tank. You could crack the porcelain.
Don't overtighten the mounting bolts on the tank. You could crack the porcelain.

For leaks at the fill valve

Step1

First, tighten all connections. If the leak persists, determine the leak's source by drying everything with a towel, then looking and feeling for water.

Step2

Turn off the water supply to the toilet, flush to drain the tank and sponge out any remaining water.

Step3

Use a wrench to disconnect the supply-tube coupling nut and remove the fill valve's mounting nut (see illustration in How to Stop a Toilet From Running).

Step4

Lift out the fill valve to clean the gasket and washer. If either is damaged or dried out, replace it.

Step5

Reseat the valve, carefully centering it in the hole and holding it vertical as you tighten the mounting nut about a half turn past the point of full contact.

Step6

Reinstall the water-supply tube and turn on the water to test it. If necessary, tighten the mounting nut a little more.

For leaks at the flush valve

Step1

Drain the tank and supply-tube coupling as described in step 1, above. Remove the tank's mounting bolts using a large standard screwdriver on the bolt and either a socket wrench or channel type pliers on the nut (see illustration in How to Stop a Toilet From Running). Lift off the tank.

Step2

With the tank upside down, pull or twist off the rubber spud washer and use a spud wrench to unscrew the large locking nut from the flush valve.

Step3

Lay the tank on its side and remove the flush valve.

Step4

Remove the beveled cone washer from the flush valve. Clean it and the spud washer with a soapy sponge (or replace them if they are in poor condition).

Step5

Reverse the procedure to reinstall the tank. Make sure the beveled side of the cone washer is facing the tank's inside and the beveled side of the spud washer is facing the bowl.

Comments

jsutton said

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on 2/18/2007 Nut frozen to bolt holding toilet to floor, bolt spins with the nut when turned. What's best way to remove nut
Any plumbers out there?
We have a cracked toilet I need to replace. As luck would have it, one of the NUTs on the bolts fastening the toilet to the floor is frozen to the bolt AND the BOLT is just spinning with the NUT when turned.
I'd like advice on how to remove the NUT so I can remove and replace the toilet.
Secondarily, the BOLT spinning isn't good news either, what should I anticipate needs to be done there to secure or replace it.

Anonymous said

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on 10/1/2007 A leaky toilet tank can cause damage.

Find the leak:
1. Check the ballcock (fill valve) for leaks where it attaches.
2. Dry the tank with a towel, then check for leaks at the tank bolts.
3. Flush the toilet, to check for leak at the tank gasket.

In most cases it will be 1 of these 3 places. If it's the flush valve or a crack in the tank, see the previous article.

1-a. For a simple ballcock leak, tighten it up, or replace it making sure it's tight to the tank.

2-a. For tank bolt leaks, the bolts will usually be corroded and the nut will be rusted so the whole thing will spin. You will need to use a reciprocating saw to cut off the nut and bolts from the bottom. A hacksaw might work, but you'll probably have to take the blade out and wrap it with duct tape to use it.

3-a. For a tank gasket leak, follow the above for removing the tank bolts, as you'll have to remove the tank. Buy a new gasket and new tank bolts and reinstall.

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