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How to Fix a Toilet Tank

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Difficulty

Beginner

Duration

Under 2 hours

A leaky toilet can be both costly and irritating. There are several reasons a toilet may leak. Troubleshoot the problem by first adjusting the water level and replacing the toilet’s flapper. If the leak is coming from around the base of the toilet, a faulty wax ring may be to blame. If none of the above works, you have a leaky toilet tank that needs repair. 


The most common internal toilet leaks are found around the fill valves, tank bolts or spud washers. Read this guide for easy-to-follow instructions on how to fix a leaky toilet tank. Find out how to replace a fill valve, tank bolt or spud washer to stop your toilet from leaking.

1

Drain Toilet

Someone prepping for a toilet repair.

Before you get started, have a bucket on hand to catch water. 


  • Turn off the water supply valve. 
  • Flush the toilet to remove all the water from the toilet bowl. 
  • Disconnect the water supply line from the tank. 
  • Sponge the inside of the tank until it's dry.
2

Replace Fill Valve

Someone replacing a fill valve.
  • Remove the float valve or fill valve using two adjustable wrenches. 
  • If you're not replacing other parts, install the new fill valve and gasket following the manufacturer’s instructions. 
  • Turn on the supply line and check for leaks. If necessary, tighten a quarter turn.
  • If you still see leaks, proceed to Step 3.
3

Replace Toilet Gasket

The inside of a toilet tank showing a gasket.
  • Remove the the two bolts that attach the toilet tank to the toilet bowl. You will need a screwdriver and adjustable wrench. 
  • Each bolt will have a rubber gasket or washer that helps prevent leaks. Replace these gaskets with new ones. 
  • You may want to also replace the metal washers, bolts and nuts as well. Or try cleaning them with white vinegar and a small wire brush.
  • If you aren't replacing the spud washer, reinstall the toilet tank. First, add the metal washers, then the rubber washers onto the bolts. Put the bolts thread side down through the tank and into the toilet bowl rim. From the underside, carefully tighten the washers and hex nuts until a seal forms. Remember to alternately tighten the nuts from side to side so the tank is even.
  • Turn on the supply line and check for leaks.
  • If you still see leaks, proceed to Step 4.
4

Remove Toilet Tank

Someone removing a toilet tank.
  • Lift the tank straight up and off the toilet base.
  • Carefully place the tank upside down on the floor on an old towel or rag.


Tip: Consider getting a helper for this step. Toilet tanks are usually in an awkward place and are heavier than they appear.

5

Replace Spud Washer

Someone putting a spud washer on a toilet.
  • Remove the old spud washer.
  • Install the new spud washer over the flush valve tailpiece.
  • Place the toilet tank back on the base and reinstall it. First place the metal washers, then the rubber gaskets onto the bolts. 
  • Put the bolts thread side down through the tank and into the toilet bowl rim. From the underside, carefully tighten the washers and hex nuts until a seal forms. 
  • Remember to alternately tighten the nuts from side to side so the tank is even.

Now that you know how to fix a leaky toilet tank, you can save yourself money and frustration. You can do this repair without the help of a professional. Toilet leaks come in all types. If your tank is leaking under the toilet, you may need to replace the wax ring or replace the toilet itself. Need help identifying a tool or material to use to fix a toilet tank? Use The Home Depot Mobile App to locate products and check inventory. We'll take you to the exact aisle and bay.

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