Look for the Leak

• Before attempting to fix a leaky garbage disposal, you must find the cause and source of the leak. Leon A. Frechette of Ask Tool Talk recommends monitoring the disposal, as well as the rest of the piping beneath the sink, while the sink is in use to ensure that the leak comes from the disposal and not a nearby pipe. If the leak does come from the disposal, work your way as far inside the cabinet where the disposal is located as possible, and use a flashlight to try to pinpoint the source of the leak.
  
  

Right Under the Sink

• Start checking for leaks at the spot where the top of the garbage disposal attaches to the sink drain. If this connection comes loose, the water that flows through the sink drain may leak out around the flange before it ever makes it through the disposal. A number of issues may cause the disposal’s connection with the sink to come loose, including rusting of the connector due to the constant moisture, eroded piping tape or putty around the connection or a bad seal.
  
  

At the Disposal

• Garbage disposals generally consist of one main chamber through which the water and food particles flow out into the rest of the plumbing system. This chamber has a pipe that connects through the bottom half of the disposal, allowing the food particles and water to pass through. Like the connection with the sink, this location where the pipe connects to the disposal has the potential for several different issues, including rusting if the connector is metal, or eroded piping tape.
  
  

Repairing the Leaky Garbage Disposal

• Unless the actual garbage disposal chamber is leaking, which would indicate eroding of the plastic material used to manufacture the garbage disposal, and requires replacing of the entire unit, the cause of a leaky garbage disposal should be reparable. Replace any piping tape or putty that has become eroded, any seals that have become stretched or torn, and any rusted metal connectors with plastic to fix the leak and help prevent future leaking.