How to Replace Valve Seats

Take the original valve seat to the store 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. As you work on your project, be sure to follow any instructions that come with your faucet or replacement part.

To complete your preparation for replacing the valve, follow the following steps:

• 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.

The next step to follow in your replacement is to turn off the water at the shut off valve under the sink.

Remove the handle by removing the screw holding the faucet in place.

Next, take out the valve by using the water-pump pliers to loosen and remove the compression valve. Set aside and save any washers and O-rings.

Select a head that fits snugly in the valve seat and place the head on the seat wrench. 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 and wait for a few minutes, then try again. 

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.

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. Turn the water on and check for leaks.