How to Replace The O-Ring on a Moen Kitchen Faucet

Over time and after regular use, faucet components begin to fail. If your kitchen faucet is dripping water, it may be time to take a look inside the faucet to see what is causing issues.

In Moen faucets, there is a cartridge with a rubber O ring. If the O-ring becomes damaged, the faucet may begin to leak. Replacing the part isn’t difficult and only needs a few minutes of your time.

To replace a faulty O-ring in your Moen kitchen faucet, follow the instructions below.

Replacing The O-Ring

First things first, you need to turn off the water supply to the faucet. Many sinks have a shut-off valve underneath, but if yours doesn’t, you’ll need to turn off the main water supply. Now that the water supply is off, you can begin taking apart the faucet.

Here’s what you’ll need for this project:

  • Flat-head screwdriver
  • Utility knife
  • Adjustable wrench
  • Hex/Allen wrench
  • Replacement O-ring
  • Plumber’s grease

Using the utility knife, carefully pry off the cap in the center of the Moen faucet handle. The set screw should be underneath. Use your hex wrench to remove the hex screw. To remove the handle, pull it off of the faucet valve. The retaining nut can then be removed with the adjustable wrench.

Replacing The O-Ring

Once the retaining nut is removed, you can lift the cartridge out of the faucet valve body. Remove the O-ring from the cartridge using the flat-head screwdriver. Now that you’ve removed the faulty O-ring, liberally apply the plumber’s grease to the replacement part.

You may be able to purchase O-ring replacement kits with the correctly sized replacement.

On single-handle faucets, you’ll need to remove the retaining nut, twist the spout back and forth, then pull it up to remove it.

Replace the O-ring, then set the cartridge back into the faucet body and replace the retaining nut. Reinstall the handle and screw in the handle screw. Snap the screw cap back into place.

Now, turn on the water supply and check for a leak.

When Should An O-Ring Be Replaced?

Each of the components in a faucet will wear down over time, including O-rings. Worn O-rings usually will cause leaks in your faucet, which is a sure sign that it needs to be replaced. Damaged O-rings may also generate pulses of high water pressure from the faucet, indicating a replacement is necessary.

Why Is My Moen Faucet Leaking After Replacing The Cartridge?

Replacing The Cartridge

If you recently replaced the cartridge in your Moen faucet to try and fix a leak, and it is still leaking, it may be time to replace the other parts in the faucet, including gaskets and O-rings. The rubber seat where the cartridge sits can become worn, causing water to leak through the gaps. A worn O-ring can also cause leaking, so remember to check that as well.

What Size O-Ring Do I Need For A Moen Kitchen Faucet?

Moen kitchen replacement part sizes vary based on the model. You’ll need to check the O-ring’s ID number, measure the size, or bring the O-ring to the hardware store with you to buy a replacement product.

On Moen single-handle kitchen faucets, the replacement size is consistent throughout each of the single-handle models. You can check your faucet manual for the dimensions or reach out to Moen for help if you are stuck. The ID number should be on the O-ring as well, though, and you can use that to find the exact size of your O-ring.