What you need
Multiple slip-joint pliers
Silicone grease (if necessary)
Teflon tape (if necessary)
Penetrating oil (if necessary)
Valve-seat dresser (if necessary)
Before you start
- Shut off the water at the main or with a shut-off valve and turn on the faucets to drain the pipes.
- Place a rag on the counter or in the sink to avoid damaging the surface with your tools.
- Plug the drain to keep from losing a screw or nut.
- Once you’ve removed the worn seat washer, check its size, thickness and type (solid or with a hole) so you can buy an exact replacement.
Take apart the faucet handle
To get to the damaged washer and replace it, first you have to remove the faucet handle.
- Unscrew the decorative cap on the handle using the multiple slip-joint pliers. On some models, the cap is just a red or blue disk (indicating hot or cold) that can be pried off.
- Remove the handle screw.
- Pull off the handle.
Remove the packing nut
- Use an adjustable wrench to unscrew the packing nut.
- If you have trouble, apply penetrating oil and wait a few minutes.
- Finish unscrewing the packing nut by hand. It’s not unusual for a small trickle of water to appear.
Check the condition of valve seat and dress it, if necessary
The seat is the surface on which the seat washer rests to prevent leaking. This part of the faucet may be damaged, worn or covered in scale (mineral deposits). If so, it’s not enough to just replace the washer. You need to dress, or smooth, the valve seat.
A valve-seat dresser (grinding tool) is made up of a handle, a retaining nut, a locknut and several cutter heads of different sizes. This is how to use it:
- Check the seat by looking at it and feeling it with your finger.
- Slide the retaining nut over the threaded shaft of the seat-dressing tool and then attach the locknut and the cutter head of the right size to the shaft of the tool.
- Select the thread gauge corresponding to the size of the head, then press the seat-dressing tool down lightly into the place where the faucet goes. Do not force it.
- Turn the tool handle clockwise two or three rotations. Remove the tool and check the seat with your finger.
- Remove any debris.
Remove the worn washer
- Pry up the washer with a screwdriver or round-tipped knife and pull. If the washer is held in place by a screw, remove it.
- Check the condition of the O-ring in the packing nut. If it’s damaged, replace it.
Replace the worn washer
- First clean the packing nut where the washer was, using a rag or soft brush.
- Insert the new washer with your fingers so as not to damage it.
Replace the packing nut
- To make it easier to replace the packing nut, apply silicone grease or wrap Teflon tape around the threads.
- Be sure the packing nut is open.
- Screw the packing nut into place by hand.
- Hold of the faucet and tighten the packing nut gently with the adjustable wrench.
Replace the faucet handle
- Replace the handle on its stem and retighten the nut to hold it in place.
- Replace the decorative cap or colored disc.
Test for leakage
- Open the water valve.
- Run the water to see whether the faucet is properly installed.
- If it leaks, remove the handle again and tighten the packing nut.
- If it still leaks, remove the packing nut, apply silicone grease to the washer and threads, and replace the nut.