Tips for Replacing the Mechanism in Your Toilet Tank

by Larry Quaynor 01/31/2021

Photo by House Method on Unsplash

Some home maintenance projects definitely require a professional. But given just how fast homeownership costs can add up, it's nice to know that other home projects are DIY for the average person. 

Replacing your toilet fill valve and the flapper is one such project. 

The toilet is one of the few items in our homes that hasn't changed much in the past couple hundred years. What does that mean for you? 

For the most part, basic mechanical principles make it work. And the great news is, if the toilet looks okay cosmetically, then replacing these mechanisms basically gives you a toilet that will function as if brand new. 

Let's get started.

What you'll need

  • An XL bucket that can hold about three to five gallons. It needs to fit under the back of your toilet.
  • Crescent adjustable wrenches
  • Rags
  • Replacement parts (fill valve, flapper and/or gasket). *Pro tip* Just look inside your toilet to see what kind of valve it uses. 

    Aside from the replacement parts, we'll bet you have most of these things at home. Replace all or some of these parts using this guide. It's up to you.

    Step one: Empty the tank

    Start by turning off the water using the knob behind your toilet. This keeps the tank from re-filling as you empty it.

    Flush the toilet. This will empty the tank partway. Don't miss this step or there will be way more water in the tank than the bucket can hold.

    Now, place your bucket behind the toilet, and carefully remove the hose from the tank but not the wall. Direct the water into the bucket.

    *Pro tip* If you have a larger than average tank, then you might have more water in it than you can fit into the bucket. Don't freak out it if it fills fast. Just place your thumb over the hole to stop the flow. Empty the bucket into one of the following:

  • Shower
  • Bath
  • Sink
  • Toilet bowl
  • Step two: remove the flapper & gasket

    The flapper simply sits on top of the hole in the bottom of the tank. Simply dislodge the hinge of the flapper and pull it out of the tank.

    Now, remove the gasket under the tank. Just unscrew the tank from the bowl. Lift the bowl carefully and set it on the floor. Remove the gasket by hand. You can then remove the valve by unscrewing it.

    *Pro tip*:  If the nut and bolt are on extra tight, you'll need one wrench to hold the nut under the tank while you unscrew from the inside. 

    Step three: replace the gasket & flapper

    Simply screw the new gasket on. Be careful not to over-tighten and strip the grooves or you'll have a more significant repair job on your hands.

    Screw the tank back onto the bowl, and then install your new valve with the lock nut, which will be under the tank. Place the flexible tube into the tanks overflow pipe.

    Now, snap the new flapper in place and that's it. Use the rags to clean up any water that spilled. Fill up your tank and go. 

    For more easy DIY projects, follow our blog.

    About the Author

    Larry Quaynor

    Larry Quaynor, your number one source for Springfield Real Estate, and surrounding towns.