Leaks can occur on a compression faucet when friction from the valve stems
causes the surface of the seat to become uneven over a long period of time. If
you’ve already replaced the compression washer, and your faucet still leaks,
it may be due to the valve seat. Repairing a worn valve seat is a project many
homeowners who are handy with a few basic tools can do themselves. You can
take the original valve seat to the store and match it to get the right
replacement part. Be aware, however, that not all valve seats are designed to
be removed, so be sure to inspect inside the faucet body. If it has a square
or hexagonal hole or a slot for a screwdriver, the seat can be replaced. If
not, you may still be able to fix the problem by resurfacing the seat. Refer
to our Resurfacing
Worn Valve Seats project guide in the related projects menu. As you work
on your project, be sure to follow any instructions that come with your faucet
or replacement part.
Before You Begin
Block the drain opening with a cloth.
If you need to replace the seat, take the original with you to the store so
you can get an exact match.
While the assembly is taken apart, consider replacing both valve seats and
replacing the O-rings, washers and bib screws.
Some faucets come with lifetime warranties on parts, so check with the
manufacturer for details.
Turn off the water at the shut off valves under the sink or at the main water
supply. To learn more about shutting off the water, watch our
to Shut Off a Valve video.
Remove the Handle
Pry off the handle cap.
Remove the screw holding the faucet in place.
Remove the Valve
Use water-pump pliers to loosen and remove the compression valve.
Set aside and save any washers and O-rings.
Remove the Old Valve Seat
Select a head that fits snugly in the valve seat and place the head on the
To remove the old valve seat, insert the wrench into the seat and turn it
counterclockwise quickly and firmly. If the valve is stuck, apply penetrating
oil or spray lubricant, wait a few minutes, then try again.
Install the New Seat
Put a new seat in the faucet and set it in place with the seat wrench.
Set the new seat by turning the wrench clockwise firmly.
Reassemble the Faucet
Before reassembling the faucet, flush any ground off debris out of the system.
Cover the hole with a rag and turn the water on gently to flush the system.
Assemble the compression valve, faucet handle and handle cap.