How to Repair a Leaking Toilet Tank

Follow these simple steps to fix a leaky toilet tank

1-2 hours

If you've tried adjusting the water level and replacing the flapper in your toilet and you’re still hearing the sound of water running, you may be dealing with a leaky tank that needs repair.

Leaky fill valves, tank bolts and spud washers are the three most common places in the toilet tank where leaks are likely to occur.

This guide provides easy-to-follow instructions on how to replace a fill valve, tank bolt or spud washer to stop your toilet from leaking.

Note: This guide tackles how to fix an internal toilet leak. To fix leaks on the toilet's exterior, watch this video.

What You Need

Prep work area and drain toilet
Prep work drain toilet - Repair Leaking Toilet Tank

• Before you get started, inspect the area where you will be working and have a bucket on hand to catch water.
• Turn off the water supply valve and flush the toilet.
• Disconnect the supply line from the tank and sponge the inside of the tank until it's dry.

Replacing a fill valve
Replacing a fill valve - Repair Leaking Toilet Tank

• Remove the fill valve using two adjustable wrenches.
• Take it with you to your local Home Depot store so you’ll be sure to get the right part.
• If you’re not replacing other parts, install the new fill valve and gasket. See our project guide on Installing a Fill Valve for details. Turn on the supply line and check for leaks. If necessary, tighten a quarter turn.

Replacing toilet gaskets
Replacing toilet gaskets - Repair Leaking Toilet Tank

• Remove the tank bolt with a screwdriver and adjustable wrench.
• Clean the bolt and nut with white vinegar and a small wire brush.
• If you aren't replacing the spud washer, reinstall bolts and nuts with new gaskets. Alternate the tightening of the nuts to evenly draw the tank tight.
• If you are replacing the spud washer, continue to Step 4.

Removing the toilet tank
Removing the toilet tank - Repair Leaking Toilet Tank

• Lift the tank straight up and off the toilet base and set it upside down on the floor on an old towel or rug.
• Make sure you have a helper -- toilet tanks are usually in an awkward place and are heavier than they appear.

Replacing the spud washer
Replacing the spud washer - Repair Leaking Toilet Tank

• Remove the spud washer and take it with you to your local Home Depot to find the right replacement.
• Install the new spud washer over the flush valve tailpiece and place the toilet tank back on the base.
• Reinstall the tank bolts, gaskets and nuts, alternately tightening the nuts from side to side so they tighten evenly.