How to Replace a Kitchen Sink Drain with Basket Strainer

The kitchen sink is one of the most heavily used areas in any home and can come across some intense usage. The sink drain and drain basket strainer are a couple of the main mechanical components to take care of in a kitchen and is relevantly easy to do so. However, since the drain undergoes frequent usage, it is subject to damage and eventual replacement. If you need a new sink drain strainer, we’ll help you with the replacement process and sourcing a basket strainer in a matching color finish.

Fortunately, replacing a kitchen sink drain is a manageable DIY project that most homeowners can accomplish with the right tools and a bit of guidance. Whether you're dealing with a leaky strainer, corrosion, or a complete break, knowing how to replace this small but essential component can save you time and money. 

Note: This replacement guide is not for drains connected to a garbage disposal. Although the process is similar, there are additional steps that further take the garbage disposal into account.

How to Know What Size Sink Drain Strainer You Have and Need

The standard size for most kitchen sink drains is 3-1/2 inches in diameter, which fits the majority of kitchen sinks. However, it’s important to note that not all sinks are the same, and there may be slight variations depending on the manufacturer or the age of your sink. Some older sinks or custom sinks might have strainers that are slightly larger or smaller, so it’s best to measure your current strainer before purchasing a replacement. Measure your current basket strainer for the most accuracy. Measure the Drain Flange outer diameter, Drain Tubing outer diameter, and your Maximum Counter/Deck thickness.

Standard Sink Drain Opening: 3-1/2 inches

Standard Drain Flange Outer Diameter: 4-7/16 to 4-1/2 inches

Standard Deck Thickness: 1 to 1-1/2 inches

View All Kingston Brass Kitchen Sink Drains

How to Measure Your Current Strainer for Replacement

1. Remove the Old Strainer: If possible, take out the existing basket strainer from the sink. If it's stuck, you can measure while it's still in place.
2. Measure the Diameter: Using a tape measure or a ruler, measure the diameter of the opening where the strainer sits. Ensure you measure from the outer edge of the drain on one side to the outer edge on the opposite side.
3. Check the Depth: It’s also useful to measure the depth of the strainer if you’re dealing with a specific type of sink, as some deeper sinks might require a different size strainer.

Accurate measurements will help make sure that your new basket strainer fits snugly and works effectively without causing leaks or other issues.

How to Remove the Old Kitchen Sink Drain 

Tools & Materials Needed

Adjustable Wrench or Pliers

Plumber’s Putty

Bucket, Bowl, or Towel

Cross-head & Flat Head Screwdriver

Penetrating Oil (optional)

Replacement Strainer & Install Hardware

Removing the old kitchen sink basket strainer is often the most challenging part of the replacement process, especially if the strainer has been in place for many years or is sealed with stubborn materials. 

Remove the Lock Nut, Drain Parts, and Drain Strainer

The lock nut is the component that secures the basket strainer to the sink from underneath. Over time, this nut and the other drain parts can become corroded, stuck, or difficult to remove, especially if it has been exposed to moisture. Here's how to remove it effectively:

1. Turn Off the Water Supply: Before you begin, make sure the water supply to the sink is turned off. This prevents any accidental leaks or spills while you’re working.

2. Place a Bucket Under the Sink: Position a bucket, bowl, or towel under the sink to catch any water that may still be in the pipes when you disconnect the drain.

3. Disconnect the Drain Pipe: Use an adjustable wrench or pliers to loosen the slip nut connecting the drain pipe to the strainer. Once the nut is loosened, carefully separate the drain pipe from the strainer, leave it in place if it is still attached to other plumbing pipes, or set it aside if it fully detaches.

4. Loosen the Lock Nut on the Drain Strainer: To loosen the lock nut that secures the strainer to the deck from underneath, use an adjustable wrench or a specialized lock nut wrench. Grip the nut firmly and turn it counterclockwise. If the nut is difficult to turn, try applying penetrating oil to help break the seal. Let the oil sit for a few minutes before attempting to loosen the nut again. If the nut is particularly stubborn, use pliers to apply extra torque and remove the lock nut completely.

5. Remove the Strainer Body: With the lock nut removed, you should be able to pull the drain housing parts down, and push the strainer body up and out from the top of the sink. If the strainer is stuck, apply pressure from underneath or use a putty knife to gently pry it loose.

How to Install the New Kitchen Sink Drain

Replacing the Kitchen Sink Basket Strainer

1. 
   Apply Plumber’s Putty to Drain Flange: If you’re using plumber’s putty, take a small amount and roll it into a rope-like shape, about 1/4 inch in diameter. Place the putty around the underside of the new strainer flange, creating a continuous ring. The putty should be thick enough to create a watertight seal but not so much that it’s too difficult to press the strainer into place. If you’re using silicone, apply a bead of sealant around the underside of the strainer flange. Be consistent in applying the silicone, ensuring that there are no gaps or thin spots.

2. Insert the Strainer into the Sink: Place the strainer into the sink’s drain hole from above, pressing it firmly into place. The sealant (whether putty or silicone) should spread evenly under the flange, filling any gaps between the strainer and the sink. Some overflow of putty or silicone is ok, you may clean this up after securing the drain. 

3. Secure the Strainer from Below

   - Rubber Gasket: Slide the rubber gasket onto the strainer’s threaded section from beneath the sink. The gasket should fit snugly against the underside of the sink.

   - Cardboard Washer: Place the cardboard washer (if included) under the rubber gasket. This washer helps protect the gasket during tightening.

   - Housing: Place the drain housing up against the rubber gasket and cardboard washer.

   - Lock Nut: Screw the lock nut onto the strainer’s threads, tightening it by hand as much as possible. Once hand-tight, use an adjustable wrench or lock nut wrench to tighten the nut further. The goal is to create a secure, watertight seal without over-compressing the gasket or putty.

4. Clean Up Excess Sealant: If you used plumber’s putty, excess putty will squeeze out from under the strainer flange as you tighten the lock nut. Use a putty knife or your fingers to scrape away this excess putty, leaving a clean edge around the strainer. If you used silicone, wipe away any excess sealant with a clean rag before it dries. Be sure to smooth out the remaining sealant around the flange for a neat finish.

5. Reconnect the Drain Pipe: Reattach the drain pipe to the strainer’s tailpiece using the slip nuts. Be sure the connection components and washers involved are in good condition. Tighten the nuts by hand, then give them a final turn with pliers if needed.

6. Final Inspection: Run the water and check for leaks from all connection points. If you used silicone sealant, allow it to cure for the recommended time (usually 24 hours) before testing or using the sink.