Most garbage disposals are sealed using plumber’s putty. You’ll need to detach the garbage disposal, clean off the old putty and reseal. Other types of disposals use only a flange that is tightened and compressed with screws. This may need to be replaced. Either way, this can be a big job if you don’t know what you’re doing (requires removing and replacing drain pipes, as well).
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.
If the leak occurred under the sink and at the top of the disposal before you unplugged the sink drain, your leak is in the sink flange. This indicates that an improper seal exists between the unit and the sink, which can occur from corrosion or the disposal being bumped hard and out of place. This fix requires you to move the disposal altogether. Then apply a generous amount of plumber’s putty to the flange. Finally, replace the disposal and retighten the flange.
Hang the disposal by aligning the three mounting tabs with the slide-up ramps on the mounting ring. Holding the disposal in place, turn the lower mounting ring until all three tabs are locked into the mounting assembly. The disposal will now hang by itself. Tighten the three mounting screws, ultimately tightening each screw a few turns at a time until the mounting assembly is evenly and tightly seated against the bottom of the sink.
Cecilia Harsch has been writing professionally since 2009. She writes mainly home improvement, health and travel articles for various online publications. She has several years of experience in the home-improvement industry, focusing on gardening, and a background in group exercise instruction. Harsch received her Certified Nurses Assistant license in 2004. She attended Tarrant County College and studied English composition.