How To Replace Flush Valve Seal In A Toilet?

Last Updated on September 1, 2022 by acechapman

Toilet brands such as Mansfield, American Standard, and certain models of Kohler or American Standard don’t use flapper flush valves. They use what’s known as a tower or canister flush valve, which uses a flush-valve seal in place of a flapper. Continue reading to know how to replace your toilet’s flush valve seal.

Canister flush valves, or tower flush valves, lift completely when the handle of the toilet is pulled down. This allows water to flow down the bowl from all sides, allowing for a powerful siphon.

The flush valve seal can warp, wear out, or become less watertight due to age, water quality, and frequency of use, among other factors. This happens when your toilet is running.

A running toilet will allow the tank to fill up automatically when it reaches a certain level. Ghost flushing is a term that describes this phenomenon.

A running toilet is not the only sign your flush valve seal has been worn out. The toilet lever will become very difficult to pull due to the pressure created by the seal. The toilet trip could even burst if it is not repaired.

HOW DO YOU CHANGE A FLUSH VALE SEAL?

• Turn off the water supply to the toilet and then remove the tank lid.
• Then disconnect the refill tube and trip from the tower.
• Take out the seal and place the new one in the groove.
• Connect the refill tube and trip to the tower.
• Test the seal by turning the water off.

If you can, use an original flush valve seal from the manufacturer. You can find generic flush valve seals on the market but they aren’t as good as the originals and will leak or deteriorate fast.

Toilet tank designs vary so I’ll show you how to change the flush valve seal on a Mansfield toilet. Next, I’ll show you how to fix a Kohler toilet. Then, I’ll show you how it works with an American Standard toilet.

HOW TO REPLACE A FLUSH VALE SEAL IN A MANSFIELD TOILET

• Turn off the water supply to the toilet. The wall behind the toilet houses the shut-off valve for the toilet.
• To remove as much water from the toilet as possible, flush it and then hold the lever down.
• Take off the lid of your toilet tank with your hands. Place it in a secure place so it doesn’t fall off.
• Then, remove the top cap from the refill tube. The refill tube is the thin tube connecting the fill valve tower to the flush valve. Simply pull the top cap off.
• Remove the top cap. You will only need to turn the stop cap counterclockwise because it is threaded on top of the tower.
• Disconnect the toilet trip and the flush valve tower. To slide the tower out, you will need to raise the tower slightly.
• Take the tower off and put it away.
• Now you can see the flush valve seal in the tank’s bottom. It is usually red.
• Take the flush valve seal out from the groove.
• Use a soft cloth to clean the groove if it looks stained.
• Make sure the new flush valve seal is in the groove before you insert it.
• Rotate the seal 360° to confirm it is securely seated and moves freely in its grove.
• Place the flush valve tower back in place. However, before pressing all the way down, connect the trip lever to the flush valve tower.
• Fix the top cap.
• Connect the refill tube and the stop cap.
• Turn off the water supply to the toilet.
• Check that the trip lever is free of obstructions and flush the toilet. If the leak persists, you can test it yourself.

REPLACING A FLUSH VALE SEAL IN A KOHLER TOILET

• Turn off the water supply to the toilet.
• To flush the toilet, hold the lever until all the water is out of the tank.
• Take off the tank lid and store it in a safe location.
• Then, take the refill tube out of the top of your canister.
• Remove the trip lever lift chain from the canister. To prevent the lift chain from becoming too tight or loose later, mark exactly where it was attached to the canister.
• Grab the top cap, or body, of the center support and turn 1/8 turn clockwise. Then lift the entire canister assembly.
• The flush valve seal is located at the bottom end of the canister assembly.
• Take the old flush valve seal from the groove.
• With a soft cloth, you can clean the groove and the bottom of your toilet tank, where the seal is.
• Continue to work the flush valve seal in the groove of your canister until it is fully in place and can turn freely.
• To lock the canister assembly in place, turn the 1/8 turn clockwise.
• Connect the refill tube to the cap’s top.
• Attach the lift chain to the canister (where indicated).
• Turn on the water supply to the toilet, and flush it multiple times. Also, check if the leak is stopped.
• Reattach the tank lid.

REPLACE A FLUSH VALVE SEAL IN AN AMERICAN STANDARD TOILET

The flush valve seal on an American Standard toilet, such as the Champion 4, will wear out and cause it to leak. Here’s how to replace it.

• Turn off the water supply to the toilet. Then, hold the handle of the toilet down to drain as much water as you can.
• Place the lid on the toilet tank and remove it.
• Then, remove the trip lever rod from the flush valve lift chains. This may require needle-nosed pliers. To avoid having to change it later, make sure you note the location of the chain.
• Remove the flapper from the top and loosen the flush valve lift chain.
• The flapper is composed of two halves. The flush valve seal is located in the groove in the upper part. Open the flapper and pull out the seal of the groove.
• Place the flush valve seal into the groove and close it.
• Connect the flush valve lift chain to the trip lever rod and screw it in.
• You can then turn the water supply to the toilet again and then test the flush valve seal.
• Reattach the lid.

American Standard has provided a video that will walk you through each step.

This is how to replace the flush seal on an American Standard toilet.

HOW TO REPLACE A FLUSH VALE SEAL IN A DUAL FLUSH TOILET

The problem is usually with the flush valve seal. You can fix it by replacing the seal.

• Turn off the water supply to the toilet
• Press the big button to flush the toilet.
• Then, take off the tank lid, and set it aside.
• Grab the flush valve assembly in the middle of your tank and turn it 1/8th counterclockwise.
• The flush valve seal is located at the bottom.
• Take out the flush valve seal and toss it.
• Use a soft cloth to clean the groove and bottom of the tank.
• Place the new flush valve seal around the groove in the flush valve assembly.
• Also, to ensure that the seal is in the groove, run your finger around it.
• To lock the flush valve assembly in place, push it back and turn it clockwise 1/8 of a turn.
• Turn off the water supply to the toilet.
• Then, you can flush the toilet several times to check if it is leaking.

This is how to replace the flush valve seal on a dual flush toilet. This guide is a courtesy to you.

Wrapping up

Depending on the water condition, you need to replace the flush valve seal in your toilet at least once every couple of years. Similar assemblies may be found on other types of toilet water tanks. It’s so simple to do it yourself, why call a plumber?

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