If you notice a puddle of water at the bottom of your kitchen sink, the basket strainer likely needs replacing. The sink basket strainer keeps dirt and food particles from clogging up the system. The leak is easy to fix with channel lock pliers or a pipe wrench, plumber's putty, and a new sink strainer. Here are some tips to fix the kitchen sink basket strainer leak.
Remove the Old Basket
First, determine the source of the leak. To test the strainer for leaks, plug the sink and fill it with water. Check underneath the sink occasionally for drips. If you see drips near the rubber gasket (piece located between drain hole and sink) or locknut, it is a strainer leak. Try tightening the locknut under the drain basket to stop the leak before removing the basket strainer.
If tightening the locknut doesn't help, you will have to take the strainer off the pipe and replace it. Shut off the water supply to the sink. Take off the coupling nut on top of the drain pipe by turning channel lock pliers or a pipe wrench to the left. Remove the locknut in the same manner.
A nut that is hard to grip may have to be cut off the pipe. Detach the rubber gasket and friction ring (paper washer) below the strainer. Lift the basket up and out from the bottom of the sink.
Clean the old putty from the sink opening with a plastic putty knife. Plastic will not scratch the sink surface. If the putty won't come off, use a wool pad. Form a golf-ball sized amount of putty with your hands, and knead for several minutes until pliable.
Roll it into a rope long enough to fit around the sink opening, and press it firmly in place. Place the sink strainer in the opening, applying enough pressure so the flange (flat metal disc that sits in the drain hole below the sink opening) is secure in the putty.
Scrape off excess putty with the plastic putty knife underneath the opening and sink strainer. Reattach the rubber washer and friction washer. Replace the locknut by turning the wrench to the right. The locknut should be secure, but not too tight. Reassemble the drain pipe, turn on the water, and check for leaks again like you did earlier.
These tips should help you fix the kitchen sink basket strainer. If your repairs don't stop the leak, you will need the services of a residential plumbing repair specialist.