How to Replace a Kohler Toilet Canister Flush Valve Seal?

How to Replace a Kohler Toilet Canister Flush Valve Seal?

You may or may not already know that the flush system of the Kohler toilets is entirely different from other common toilets we have in the market. This greatly different flush system requires more care and has to be fixed very efficiently in case it starts having some issues.

One most common issue that occurs is that the Kohler canister toilet keeps running. This problem points directly to the loosened flush valve seal. Hence, the solution is: replace the flush valve seal, here is what you need to do:

Make sure that the toilet’s water supply is turned off. As you turn the white refill tube counterclockwise (a 1/4 turn), it connects to the center of the guide, which is located in the center of the canister. Remove the canister from the tank.


Now, you will need to replace the red or yellow seal underneath the canister. Then, line up the slots of the flush valve and the tab on the bottom of the canister to install the new canister. Lock the canister into place by rotating it clockwise.

Amazingly, it is not a long, difficult procedure to replace the flush valve seal.

What Flush Valve Seal Do I Need?

What Flush Valve Seal Do I Need

While replacing a flush valve seal, it is important to find the correct size of it. The size of these valve seals may differ according to the type and model of the toilet you have. In the case of a Kohler Toilet, a good observation may lead you to an easy decision. Here is how:

  • For the size of oranges or baseballs, the seal should be around 2 inches long.
  • A 3-inch jumbo seal will be required if the seal looks the size of a grapefruit or softball.
  • It is also possible to gauge the flapper size by measuring the flush valve opening.

If you could not decide it on your own, you can simply contact a professional and he would guide you through everything that’s suitable for your particular toilet.

Other than the size of the flush valve, what really matters is a high-quality valve. Obviously, you wouldn’t want to get your valve replaced every couple of months. So, a good quality valve would do a great job for a long time.

Is There a Seal Between the Toilet Tank and Bowl?

Also known as a spud washer, a toilet tank to bowl gasket seals the toilet tank to the bowl by a rubber gasket. It is normally mounted outside the flush valve at the point where the water exits the tank and enters the bowl.

When your toilet leaks between the rim of the tank and the bowl, it means that the tank-to-bowl gasket has worn out, the bolts have come loose, or the flush valve has been damaged. But these issues can surely be solved and there are certain ways to fix them.

How do I know my Kohler toilet model?

You can find the model number by looking for it inside the tank. It is usually stamped with a spot of blue ink or sometimes molded into the china. The complete model number consists of four or five digits and a K prefix may be included. For some models, the number is preceded by F or 97.

How to Replace a Kohler Toilet Canister Flush Valve?

Replacing the Kohler toilet canister flush valve seal becomes mandatory when your toilet keeps running. But this isn’t something to worry about. The replacement of flush valve seal is an easy and quick task which you can definitely do it by yourself as well.

But, there might be some people who don’t prefer doing this themselves. So, they’ll prefer hiring a professional instead. In that case, too, it would take only a few minutes and won’t require you to spend a lot of money because it’s simply an inexpensive task.

Kohler Toilet Flush Valve Seal Replacement

Here is a complete procedure you would need to follow for the replacement of the Kohler toilet flush valve seal.

  1. Turn Off the Toilet’s Water Supply
  2. Remove the Seal
  3. Install a New Flush Valve Seal
  4. Verify That the Toilet Does Not Leak

Kohler Toilet Flush Valve Seal Replacement

1: Turn Off the Toilet’s Water Supply

  1. Behind the toilet is the shutoff valve. The valve must be turned clockwise and the push and pull valve must be fully pulled out.
  2. Maximum water should be removed from the toilet by flushing and holding down the handle.

2: Remove the Seal

  1. Remove the lid of the toilet tank, taking care to store it safely.
  2. Make sure the chain is in good shape. There should be enough slack in the chain but not too much tightness.
  3. The fill valve is connected to the refill tube. As part of a refill, water is sent down the refill tube to the bottom of the bowl. Gases from sewers are blocked by this water. Your task here is to disconnect the refill tube. You can simply pull the refill tube away from the canister guide.
  4. Remove the lifting chain from the canister and raise it up. Rotate the canister guide 1/4 turn counterclockwise to remove it. Stack the assembly upright and lift it out.
  5. Remove the seal from the groove by pulling it out.

3: Install a New Flush Valve Seal

  1. The opening of the flush valve and the groove in the canister should both be cleaned.
  2. Then insert the new seal. Ensure that the new seal is seated in the groove of the canister by running your fingers around it.
  3. The bottom tab of the guide must be aligned with the flush valve placement in order to install the canister. Fix the canister in its slot by rotating the guide 1/4 clockwise turn.
  4. Attach the lift chain to the canister. Then place the refill tube atop the guide.

Finally, connect the toilet’s water supply.

4: Verify That the Toilet Does Not Leak

  1. Put the lid of the tank back on, once the new toilet flush valve has been installed. Fill the toilet tank with water by opening the shutoff valve on the toilet.
  2. If you use a flashlight and paper towels to check the bottom of the tank, you will quickly find out whether the moisture is leaking or not.

PRO TIP: Listen for leaking water once the tank has filled, and wait for the tank to begin filling again on its own. The flush valve needs to be replaced again if either of these two signs is present.

Why Does Kohler Use a Canister Flush Valve?

Normally, toilet flappers have one hinge. In order to flush the toilet, the flapper must be lifted to allow it to swing away from the hinge. Alternatively, the cylindrical canister flush valve allows water down the bowl with an angle of 360 degrees by lifting off vertically.

Because of this, more water enters the bowl quickly, creating a stronger flush. There are 3:2 ratios between the entrance and exit of the flush valve. Consequently, this narrow portion of the flush valve causes the water to exert more pressure. Hence, the greater the pressure, the more powerful the flushes are.

Kohler Canister Flush Valve Problems

Kohler toilets have often faced problems related to the canister flush valves. You might sometimes experience leaky valves, loosened screws, or the occasional running toilet. As the toilet ages, it may even develop hairline cracks.

It is possible to repair some problems, but replacing some parts is necessary for others. There are temporary solutions to some problems while permanent solutions for others too.

Some common canister flush valve problems include:

Kohler Canister Flush Valve Problems

Running Toilets

The fill valve is usually the cause of a running toilet. Some cases could be triggered or facilitated by water pressure as well. In order to overcome this problem, you’d have to replace the canister flush valve seal.

Unsuitable Water Pressure

Sometimes, the problem with the Kohler canister flush valve is the inappropriate water pressure. In such a case, A water pressure check or a look at the amount of water in the tank would be helpful. The main inlet valve can be used to reduce water pressure. Float valves in tanks may be lowered to reduce the amount of water.

Flush Problems

It is possible that there are issues with the flush. In certain cases, the flushing pattern may be irregular or too weak. Sometimes a blockage may be the cause of interrupted flushing or a weak flushing pattern.

Verify the outlet, rim wash, as well as flapper chain. The damaged part should be repaired and the tank should be cleaned, including the inlet and outlet. If the problem is caused by the chain, it can also be solved by tightening it.

Our Verdict

Replacing a Kohler toilet canister flush valve seal is quite easy and inexpensive along with being a less time-consuming task.

There’s nothing to be worried about in case of having some issues with the flush valve seal. Because that’s a pretty common issue that can be easily fixed by your own self or you can also look for some professional to get it done for you.

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