How to fix a slow-draining sink with a pop-up drain stopper?

 
Gather Tools and Materials
 

• Protective gloves
• Screwdriver (flathead or Phillips, depending on your drain stopper model)
• Adjustable wrench
• Bucket
• Old toothbrush or small cleaning brush
• Drain cleaning solution or a mixture of baking soda and vinegar
• Paper towels or a small rag

 
Remove the Pop-Up Drain Stopper
 

• Locate the lever mechanism behind the drain at the sink’s interior; this typically controls the pop-up mechanism.
• If your stopper is connected by a pivot rod underneath, look under the sink where a horizontal rod connects to a vertical lift rod. You may need to unscrew the connecting nut by hand or with an adjustable wrench.
• Once the connection is loosened, gently pull the pop-up stopper from the drain. Be cautious as the stopper may have built-up grime or residue.

 
Disassemble and Inspect the Internal Mechanism
 

• After removal, examine the pivot rod, clip, or any other linkage for debris, corrosion, or breaks. Small parts may have accumulated soap scum and hair that hinder smooth movement.
• Lay out the parts in the order they were connected so you can reassemble them correctly.

 
Clean the Drain Stopper and Linkage Components
 

• Use warm, soapy water and a toothbrush or cleaning brush to scrub the pop-up stopper. Remove all grime that may be blocking water flow.
• Soak the individual mechanical parts in the mixture of baking soda, vinegar, or a mild drain cleaning solution. This can dissolve mineral deposits and accumulated debris.
• Rinse every part thoroughly and inspect for damage or wear. Replace any deteriorated components if necessary.

 
Clean the Drain and P-Trap
 

• Pour a small amount of cleaning solution directly into the drain to help break up grease and hair clogs.
• If water still drains slowly, place a bucket under the P-trap (the curved pipe beneath the sink) and unscrew the slip nuts carefully. Be ready to catch any residual water.
• Remove the P-trap and clean inside it using a brush or a long, flexible tool inserted from both ends to dislodge any blockage. Rinse it with warm water before reinstalling.

 
Reassemble the Drain Stopper Assembly
 

• After cleaning all parts and ensuring that they are free from buildup, reassemble the pop-up mechanism in the reverse order of removal.
• Ensure that the pivot rod and linkage connect correctly, the clip is in place, and the vertical lift rod is secure. Tighten any slip nuts carefully.
• Test the reassembled mechanism by filling the sink with a small amount of water and then activating the pop-up lever. The stopper should move smoothly without resistance.

 
Test the Drainage and Check Additional Issues
 

• Run water through the sink to ensure that it drains quickly and steadily. If draining is still slow, minor clogs might persist in further sections of the drain line or venting system.
• Inspect the vent pipes (which allow air to enter the plumbing, ensuring proper drainage) for obstructions. A clogged vent can cause slow drainage even if the stopper and P-trap are clear.
• Consider that variations in water quality, as observed in St. Louis and Nashville, can occasionally influence overall drainage efficiency.
• If needed, consult a professional plumber to inspect and clean deeper sections of the plumbing system.