Miles SinclairBy Miles Sinclair

Updated November 2026

Learning how to fix a leaking faucet kitchen models share in common comes down to three things: shutting off the water, identifying where the leak is coming from, and replacing the worn part. Most drips trace back to a cartridge, a valve seat, or a set of O-rings, and each of these is inexpensive and manageable for a home repair. This guide walks through the process for most single-handle kitchen faucets.

Step 1: Shut Off Water and Identify the Leak Type

Close the under-sink shutoff valves, then open the faucet to drain remaining water. Check where the water appears. A constant drip from the spout usually points to a worn cartridge or valve seat. Water leaking from the base or handle points to O-rings or a loose mounting nut. Water pooling under the sink suggests a supply line or connection problem instead.

Shopping for one? See our guide: Fix Moen Kitchen Faucet: 5 Best Repair Parts Compared (2026).

Step 2: Remove the Handle and Access the Cartridge

Pry off the decorative cap on the handle, then remove the handle screw with a hex wrench. Lift the handle straight up. Unscrew the cap nut or retaining clip that holds the cartridge in place. Pull the cartridge out, noting how it sits, since orientation matters on reinstallation. Many owners photograph each part before disassembly to make reassembly easier.

Check the Valve Seat

Inside the faucet body, look for mineral buildup or pitting on the valve seat. If the seat is rough, a seat wrench can remove it so you can install a new one. Clean deposits with white vinegar and a soft brush.

Step 3: Replace Worn Parts

Install a replacement cartridge that matches your faucet brand and model. Cartridges are model-specific, so bring the old one to the parts counter or check the manufacturer’s parts diagram before buying. Replace all O-rings and rubber gaskets at the same time, using plumber’s grease on each one. Reassemble in reverse order, then turn the water back on slowly and test the faucet at low and high flow.

Leak location Likely cause Fix
Spout drip when off Worn cartridge or valve seat Replace cartridge, clean or replace seat
Base of spout Failed O-rings Replace O-rings
Handle area Loose handle or worn stem seal Tighten or replace seal
Under sink Loose supply line or fitting Tighten or replace connector

Tools and Supplies Checklist

  1. Adjustable wrench and hex (Allen) key set
  2. Replacement cartridge, O-rings and seals matched to your model
  3. Plumber’s grease
  4. Soft cloth and white vinegar for cleaning
  5. Bucket or towel to catch residual water

For model-specific guidance, see How to Fix a Leaky Kitchen Faucet: 5 Steps for Most Models and Moen Kitchen Faucet Dripping: 6 Causes and How to Fix Each One. If you are working on a Delta, Leaky Kitchen Faucet Delta: How to Find and Stop the Drip (Step by Step) covers that brand’s common failure points. Owners with a parts diagram in hand often finish faster, so Moen Kitchen Faucet Parts Diagram: How to Find and Use Yours is worth a look before you start.

Common Mistakes and Tips

  • Skipping the water shutoff step, which can flood the cabinet.
  • Buying a generic cartridge that does not match the faucet brand and model.
  • Reinstalling a cartridge in the wrong orientation.
  • Overtightening the cap nut, which can crack plastic components.
  • Forgetting to replace all O-rings, leading to a second leak within weeks.
  • Plumber’s grease: Lubricates O-rings and reduces wear on reassembly. View on Amazon
  • Hex key set: Most handle screws on kitchen faucets require a hex key. View on Amazon

FAQ

Do I need to replace the whole faucet to stop a leak?

Usually not. Most leaks come from a worn cartridge, valve seat or O-rings, which are replaceable parts. Replacing the entire faucet is only necessary if the body itself is cracked or corroded.

How long does this repair take?

For most homeowners, the job takes between one and two hours, depending on access under the sink and how stubborn the cartridge is to remove.

Can I use any cartridge if it fits?

Cartridges that look similar may differ in internal design and flow, so use a part that matches your brand and model. If you are unsure, consult a plumber or the manufacturer before installing.

Conclusion

Fixing a kitchen faucet leak is usually a matter of identifying the source and replacing the worn cartridge, seat or O-rings. Work slowly, photograph each step, and use parts matched to your faucet. With the right parts on hand, most repairs can be completed in one afternoon.

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Miles Sinclair

About Miles Sinclair

Miles Sinclair is part of our editorial team and reviews and edits our kitchen faucets & sinks guides, checking product details against manufacturer specifications and owner feedback.