How to Fix a Leaking Garbage Disposal

Father and son fixing pipe under kitchen sink
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Project Overview
  • Working Time: 30 mins
  • Total Time: 30 mins
  • Skill Level: Intermediate

A leaking garbage disposal is an annoyance you might run across from time to time. It's important to remember that just because a garbage disposal is leaking does not always mean you need a new one, and you might not need to call a plumber for an expensive fix. Doing a little bit of detective work and troubleshooting before replacing a garbage disposal can save you money.

Here are two of the most common causes for a leaking garbage disposal and how to fix them.

What You'll Need

Equipment / Tools

  • Wrench or pliers
  • Screwdriver

Materials

  • New gasket
  • Plumber's putty

Instructions

When the Leak Comes From the Gasket

If the garbage disposer is leaking from the very top rim where the rubber seal mounts to the flange, the cause could be the rubber gasket on the top of the garbage disposal.

When the rubber gasket gets old it can develop a leak. Long periods when there is no water in the drain and garbage disposal can cause the gasket to dry up and leak. If you remove an older garbage disposer for any reason and then put it back, it may require a new rubber gasket to get a watertight seal again. Finally, if the gasket is not locked evenly on all three sides, it will leak.

The leaking garbage disposal gasket can be easily replaced. You can find a replacement rubber garbage disposal gasket at a local hardware or home improvement store.

  1. Disconnect the Water and Electricity

    To remove the gasket and replace it you will first have to disconnect the drain and unplug the cord to the garbage disposal. If you have a dishwasher you will have to remove the dishwasher drain hose from the garbage disposal.

  2. Remove the Disposal

    With the drains and cord removed you can now take hold of the sides of the mounting nut with the appropriate wrench and twist it counterclockwise to unlock the garbage disposal. The disposal should drop straight down.

  3. Install the New Gasket

    Set the garbage disposal down where you can work on and see the rubber gasket. Peel off the old gasket and put the new gasket in the same place, making sure that it pops into the lip and sits flat.

    Tip

    Your garbage disposal may need a special gasket. To ensure that you get the right gasket, make a note of the garbage disposal model or take the old gasket into the store to match it up with a new one.

  4. Replace and Test the Disposal

    Now you are ready to set the garbage disposal back in place. Use your knee or a helper to lift the disposal into place while looking down at it from above the sink. Verify that the gasket sits flat before locking it back into place.

    Look underneath the sink to make sure that all mounting grooves are locked in. Reconnect the drains and plug the cord back in. Turn the water on and run the disposal to test it for leaks.

When the Leak Comes From the Flange

Another common cause for a leaking garbage disposal is the disposal flange. A leak at the upper area of the garbage disposal could be the garbage disposal flange, which goes through the sink. A garbage disposal flange should be sealed with plumber’s putty and then tightened from underneath the sink. If this is not tight enough or if it has managed to come loose, then the garbage disposal will have to be taken down so the flange can be resealed.

  1. Turn off the Water and Electricity

    Disconnect the drain and unplug the cord to the garbage disposal. If you have a dishwasher you will have to remove the dishwasher drain hose from the garbage disposal.

  2. Remove the Disposal

    With the drains and cord removed you can now take hold of the sides of the mounting nut with the appropriate wrench and twist it counterclockwise to unlock the garbage disposal. The disposal should drop straight down.

  3. Remove the Flange

    Loosen the bolts that tighten the flange in place. Then locate the clip that holds the bottom flange in place. Use a screwdriver to pop the clip out of its groove. Then pull the top flange out from the top of the sink.

    Tip

    Clean the area around the sink opening before reinstalling the flange, making sure to remove any old putty.

  4. Reseal the Flange

    Roll out a generous amount of plumber’s putty to a uniform width, making a snake-like gasket out of putty. Wrap the putty onto the rim of the flange.

    Push the flange back into position and put the bottom flange on with the clip holding it into place. Tighten the screws evenly until all are tight. Scrape off any extra putty from the inside of the sink.

  5. Finish the Repair and Test Your Work

    Lock the garbage disposer back in place, reconnect the drains, and test for leaks.