How to Replace Kitchen Sink Drain Pipe

​Pipes for a kitchen sink. Do you have leaks in the drain pipes beneath your kitchen sink? Or should I clear the clog in the kitchen sink? It's time to discard that bucket that keeps dripping. Tightening the joints and straightening the pipe can stop certain leaks. However, changing your under-sink plumbing is the solution if your stripped nuts won't tighten and your old washers won't seal because they're too stiff or warped. It might not be as difficult as it sounds. Installing a new drain assembly is a sensible and dependable solution, particularly if your current pipes are outdated, as plastic pipe is reasonably priced and quite simple to install.

How to replace kitchen sink drain pipe

Tools Required for Repairing Kitchen Sink Pipes

The following are the instruments needed for the project: a hacksaw, a "4-in-1" screwdriver, pliers, "slip joint" pliers, a level, and a tape measure. It may be necessary to use additional tools based on the kind of issues you run across.

The following supplies are needed for the project: PVC waste arm, rubber washer, plumber's putty, cardboard washer, basket strainer, and locknut. These items are covered in more detail later in the article, but the parts you'll need for a new drain assembly should be available in a kit at any hardware shop for less than $20 to $30.

Replace Kitchen Sink Pipes

(1): Disassemble the Old Drain

To remove the strainer, which is probably the source of the leak, disassemble the current drain assembly. The strainer is visible in the image below as the black area directly beneath the sink's white bottom. As indicated, turn the slip nuts counterclockwise. Note that in order to prevent the pipes from rotating, you must use the second set of pliers that are clamped or held onto the pipe part below the wrench displayed. The entire drain pipe assembly is not what you want to turn—just the slide nut.

After completely unscrewing the slide nuts, lower the pipe assembly and take it out.

​Plumber's putty, placed between the strainer's top flange and the kitchen sink's drain hole, serves as the main seal surrounding a basket strainer. However, this seal is temporary. It may become harder, shrink, or crack with time. Tightening the locknut can occasionally be used to stop a leak. But a fresh application of putty is frequently the sole remedy.

The Most Difficult Section

Unscrewing the old locknut on the underside of the sink is the most difficult step of removing the strainer. The strainer is secured in place by means of this locknut. If you are fortunate enough to have a "third hand," you can have your assistant insert pliers into the holes in the strainer from above and use a screwdriver to insert between the pliers' two handles to prevent the strainer from turning while you attempt to release the locknut below.

​Mineral deposits or rust frequently "weld" or seal this locknut in place. The term "spud wrench" or "locknut wrench" refers to a unique type of wrench made specifically for use with locknuts. Large slip-joint pliers with a 3-1/2-inch jaw opening will also function, and you can utilize them for further tasks afterwards. The locknut may not budge no matter what tool you try. The only thing to do in that situation is to give the locknut a single, clean cut using a hacksaw blade. It's nearly hard to accomplish this without severing the strainer threads, thus a new strainer is obviously required.

(2): Basket Strainer Assembly

​Installing the new strainer assembly now requires plumber's putty, a new locknut, rubber, and cardboard washers. After dropping the strainer in from above the sink, fill the hole around the perimeter with plumber's putty between the top of your sink and the strainer's flange. Screw the locknut into place, making sure to place the cardboard and rubber washers between the top of the locknut and the underside of the sink. Make sure to remove any leftover plumber's putty that could have escaped around the strainer's lip.

(3): Attach Drain pipe assembly tailpiece to the to Strainer

​Using the tailpiece washer in between the strainer's bottom and the tailpiece pipe, attach the tailpiece to the basket strainer. Don't tighten it all the way though, as you'll need to take it off later to trim it.

Either a side outlet assembly or a center outlet assembly could be present. You can get the parts needed for either setup at your neighborhood hardware store, depending on which one you have. The majority of the necessary components should be included in the kits for either the side outlet assemblies or the center outlet assemblies (where the trap is located beneath the center of the sink). However, you might also require the following extras, which are stated below:

• longer pipe tailpieces—many of the kits' included tailpieces are only a few inches long.
  
• An extender for the trap arm pipe (the arm included in the package might not reach the drainpipe that sticks out of the wall).
  
• If you own a dishwasher, a wye pipe piece that connects to the dishwashing hose.
  
• If you have a garbage disposer, you can connect the waste arm pipe part to it with a "disposer kit." 

​Be aware that you will need to cut the waste arm, maybe the trap arm, and both tailpieces of the new PVC pipe. The best tool is a fine-tooth hacksaw.

​When in Doubt...

Mark and cut the pipes a little bit longer when in doubt. Cutting twice is preferable to cutting too short and needing to make a second trip to the hardware shop.
Remember to tuck in the tailpiece washers. Cone washers are needed for other joints. The ground joint at the trap is the only one without a washer. Once more, all may be seen by clicking the above link. Till the entire assembly is finished, assemble everything loosely. Next, tighten each and every slip nut. It is necessary to hand tighten the slip nuts. However, after testing the rebuilt assembly, if any joints leak, use the slip-joint pliers to tighten them just a bit further. 

Installation

It could be necessary to replace the adapter on the waste drainpipe and join the PVC pipe and steel drainpipe with a rubber coupler. The steel drainpipe and PVC pipe are joined by a rubber coupler. There should now be an adaptor attached to the end of the existing drainpipe that emerges from the wall. This adapter ought to function similarly to the other joints in your drain assembly and have a washer and slip nut. You should not experience any issues if your drainpipe is made of plastic. However, if your drainpipe is made of old galvanized steel, you may have corrosion that makes it very impossible to release and retighten the slip nut.

You will need to avoid these dated discussions if that is the case. If you can, unscrew the old slip nut. If not, use a hacksaw to cut it off, being careful not to cut into the threads of the drainpipe too deeply. After that, you'll need to buy cement, a rubber transition coupler (similar to an automobile radiator hose coupler/connection), a spare piece of plastic pipe, and a plastic trap adaptor. PVC (white) or ABS (black) pipes and adapters are available; it's crucial to use the appropriate cement for the type of plastic (PVC also needs "purple primer"). Attach the adaptor to a 4-inch straight pipe using cement, and then use the rubber stopper to connect the plastic pipe to the old metal pipe.

(4): Check for Leaks in the New Assembly After You're Done

Replacing the pipes in your kitchen sink could provide challenges. Never forget that AC Repair Burke Plumbing, Heating, and Air Conditioner is here to assist you at all times. Contact us or give us a call at  703 721 4847. We would be happy to visit your house and be of assistance!

How to replace kitchen sink pipe