Locate the leak. Wipe off the disposal unit with a dry rag. Run water into the unit and turn it on. There are four places where the disposal unit may leak. At the top main seal, at the drain pipe, at the optional dishwasher inlet or along the garbage disposal body. Notice where the water is coming from. If the unit is wet at the very top, the main seal is leaking. If the area beneath the drain pipe is wet, the gasket is leaking. If the hose from the dishwasher feed drips, the hose or clamp may be faulty. If water is running out the bottom of the unit but the inlets and outlet are dry, the unit itself has developed a leak and must be replaced.
• Run water before and after you use the disposal If something has been put in the disposal that should not have been, use tongs or pliers to pull the material out. Never use your hand. To clean a garbage disposal of built-up sludge and debris, fill it with ice cubes and a cup of rock salt and then run it for about five seconds. If your garbage disposal smells bad, you can deodorize it by running warm water down it while you grind a quartered lemon.
Another common cause for a leaking garbage disposal is the disposal flange. A leak at the very most 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 (which can happen) then the garbage disposal will have to be taken down so the flange can be resealed and then the garbage disposal can be rehung.