A garbage disposal can leak from the sink flange, dishwasher connection, discharge pipe, or lower housing. Drying the assembly and watching where the first drop returns usually identifies the area; before touching connections, disconnect appliance power and control the water.
Dry the unit and find the first returning drop
Place paper or a tray below, dry the connections, and run a small amount of water with the disposal off. A drop beginning at the top can travel down the housing and look like a bottom leak, so trace moisture to the highest wet point.
A flange leak appears at the sink connection
If water starts where the disposal meets the sink, the flange seal or mounting may have failed. A proper repair requires disassembly and resealing; smearing caulk around the outside is not a durable fix.
The dishwasher hose and discharge pipe have their own seals
With power disconnected, inspect visible clamps, gaskets, and screws. Replace a cracked hose or distorted gasket; overtightening a plastic connection can create another leak.
Water from the lower housing often means replacement
If the first moisture comes from a sealed body seam or the bottom rather than external plumbing, the housing may be corroded or cracked. Do not open the motor or try to seal an internal leak near electrical components.
Sources
- U.S. Environmental Protection Agency WaterSense — Home Maintenance — Household maintenance related to water, leaks, and efficient use.