At some point, chances are good you, as a homeowner, will have a leaky drain. A drain will usually begin to leak when it is a few years old. After several years, the putty will dry out, the connections will become loose, or the pipes will begin to crack. Whatever the reason, having a good understanding of how to fix a leaky drain is important and will help you fix leaks before they cause even more damage.
Step 1- Disassemble Drain
The first step in fixing a leaky drain is determine where the leak is originating. If you have determined that the leak is from the drain itself, then begin to disassemble the drain by using a plumber's wrench. Remove all the trap fittings that you can unscrew without using a tool. For some of the traps you will need to use a screwdriver to remove fittings.
Loosen the tail piece of the drain with an adjustable pipe wrench and remove it from the sink. Remove the plastic retainers and take off the drain pipe.
Step 2- Clean All Pieces
Once you have take the entire drain assembly apart, then you will need to clean each piece thoroughly. Set each piece in a bucket of warm water and soap. You might even need to use some baking soda or vinegar to remove some of the caked-on putty and inside corrosion. Let the pieces soak to loosen up the hardened debris before you try to scrub it off. Pay attention to the putty that is left on the connections. If there is any putty left on the piece left when you begin to install it, it will interfere with the new putty and cause another leak.
Step 3- Reassemble Drain
After everything has been cleaned off and dried completely, you can begin to reinstall the drain. For each connection that you have, apply a thick coating of plumber's putty. Apply a 1/2 inch layer around the drain pipe. Lower the drain pipe back into the drain and reattach the pipe to the fittings underneath the sink. Put together the tailpipe and traps and make sure all connections are tight. Once everything is back together, turn the water on and let it run for a little while to check for any more leaks. If you find any, it might be because the putty was not applied correctly or the connections are too tight.
Step 4- Do Not Over-tighten
It is hard to believe that a connection that is too tight will actually lead to more leaks. However, because of the compression around the pipe, when you over-tighten the connection it warps the pipe and the threads, and will allow for water to pass through it. To fix the problem, take your adjustable pliers and loosen the connection a little bit. If the leak gets worse, then there is another problem. Do not be surprised to see the leak stop. Wipe off any excess putty or water, and check for more leaks.