Replacing Kitchen Sink Drain Pipes

Replacing the drain pipes under your kitchen sink is a relatively simple plumbing project that can be completed in a few hours. By following these step-by-step instructions, you can save yourself the cost of hiring a plumber.

Tools and Materials

Adjustable wrench
Plumber's putty
Drain cleaner
Bucket
New drain pipes
Slip joint pliers

Step-by-Step Instructions

1. Turn off the water supply to the sink. There should be two shut-off valves under the sink, one for the hot water and one for the cold water. Turn both valves clockwise to close them.

2. Remove the old drain pipes. Place a bucket under the sink to catch any water that may drip out. Use an adjustable wrench to loosen the nuts that hold the drain pipes in place. Be careful not to overtighten the nuts, as this could damage the pipes.

3. Clean the drain holes. Use a drain cleaner to remove any gunk or buildup from the drain holes. This will help ensure that the new drain pipes fit properly.

4. Apply plumber's putty to the new drain pipes. Roll a small amount of plumber's putty into a rope and place it around the base of each drain pipe. This will help create a watertight seal.

5. Insert the new drain pipes into the drain holes. Tighten the nuts on the drain pipes by hand until they are snug. Then, use an adjustable wrench to tighten the nuts further, but be careful not to overtighten.

6. Turn on the water supply to the sink and check for leaks. Open both shut-off valves under the sink to turn the water back on. Check the connections around the drain pipes for any leaks. If you find any leaks, tighten the nuts further until the leaks stop.

Tips

If you are replacing the drain pipes because they are clogged, be sure to clean the P-trap before installing the new pipes. The P-trap is the U-shaped pipe that is located under the sink. It collects gunk and debris, which can cause clogs.
If you are not sure what size drain pipes to buy, take the old pipes to the hardware store with you. The staff at the hardware store can help you find the right size pipes.
If you are having trouble loosening the nuts on the old drain pipes, you can use a penetrating oil to help break them loose.