Symptoms
- Water drips from the top edge where disposal meets sink
- Leak appears mainly when sink is full or draining
- Water stain on the underside of the sink flange
- Cabinet floor damp near the drain
Likely causes
- CommonDried out or failed plumber's putty at the sink flangePutty shrinks and cracks over years, breaking the seal.
- CommonLoose mounting screws on the sink flange assemblyVibration from disposal use can loosen the three mounting bolts.
- PossibleCracked sink flange or gasketPlastic gaskets can crack, especially with hot water or age.
What to do
- Turn off and unplug the disposal.
- Support the disposal from underneath, then loosen the mounting ring using the tabs or a screwdriver as your model requires.
- Lower the disposal to expose the sink flange and remove the old putty.
- Clean the sink opening and flange thoroughly with a rag.
- Apply a fresh rope of plumber's putty around the flange and reseat it in the sink drain hole.
- Reinstall the mounting ring and gasket, then tighten the mounting bolts evenly.
- Reconnect the disposal, run water, and check for drips before restoring power fully.
Tools and parts
- Screwdriver
- Plumber's putty
- Rag
- Bucket
Plumber's puttySearch: “plumber's putty sink drain”
Disposal mounting gasket kitSearch: “garbage disposal flange mounting kit”
When to call a pro
If the flange or mounting ring is cracked or corroded and won't reseal, a plumber can replace the mounting assembly.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.