Kitchen Sink Plumbing – How to Replace a Kitchen Sink Trap

Kitchen Sink Plumbing – How to Replace a Kitchen Sink Trap

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I cover the steps to replace the kitchen sink plumbing. From the kitchen p trap and the drain pipes to the sink baskets.

You will need a pipe wrench or a large adjustable pliers to work on your under sink pipes.

If you are removing the old kitchen sink plumbing, have a bucket handy to place under the trap. You will want to remove the two nuts on the trap first and remove it. It will then be easy to unscrew and remove all the other pipes that need to be replaced.

For kitchens with two sink bowls you want to look at the main drain pipe that goes into the wall and see if it is somewhat centered, or off to one side. If this pipe going into the wall is in the center, you will want to use a center outlet kit that has two drain pipes going to one tee that is centered between them. If the main drain is off to one side then you would want to use an end outlet kit that will put the trap under one of the bowls and allow it to be lined up with the main drain.

If you are putting on new sink baskets. Put them on first and save the tail piece washer that comes with the kit. If you are keeping the old sink baskets, it is good to pick up new tail piece washers to connect the new under sink drain pipe.

To replace the drain pipes for a kitchen sink, you want to start with the small tail piece that attaches to each sink basket first. To attach this pipe to the sink basket, you will want to use a tail piece washer. This is a special washer that has a flange on one side that goes into the tail piece and a flat side that sits flush against the sink basket. If your sink basket if metal, you should use a metal nut to attack the tail piece, even if you are using plastic. If it is a plastic basket, use plastic nuts.

After attaching the tail piece to each sink basket you will connect your end or center outlet. I like the plastic drain pipe. The pipe will last a lifetime and is less expensive. I also prefer nylon washers rather than rubber washers. They last longer. On nylon washers, have the wider end toward the nut and the beveled edge going into the slip joint of the next part. When you line up your tubes that connect to the sink baskets, you will check to see if they are the correct size, if not, you will cut one of the tubes to size and tighten them down.

With your pipes attached to the sink baskets, you will now connect the wall tube to the main drain pipe going into the wall. If it is a metal pipe, use a metal nut to attach the wall tube. The wall tube is the tube that connects to the bottom part of the trap and goes into the main drain. Now that you have your wall tube in place you can see how the trap will connect between the wall tube and the tee connecting the sink baskets.

The trap can be turned and positioned to line up to both the tube coming from the sink baskets and the wall tube. If there is a gap and the tube coming from the baskets is not long enough, you will need an extension tube to connect the trap. You can cut the extension to size. If the wall tube needs to come out from the wall, you can attach an extension tube to the main drain to extend it. If you are attaching a dishwasher to the trap, you would now use a special extension with a hose fitting for the drain tube from the dishwasher. If you are connecting a dishwasher, the tube has to be above the trap.

Tighten all the nuts and check for leaks.