Repairing a leaking bathroom faucet is a fairly easy job even if you have limited do-it-yourself repair experience. The main thing you need to know going in is what type of faucet you have. Determining the number of handles should be easy, but determining the type of valve inside might require a glance at the owner's manual or simply starting the process and seeing what is inside.

The valve is what controls the flow of either the hot or cold supply line when using one of the handles on a double handled faucet. A compression or reverse compression valve is one of the more simple design styles, which makes for an equally simple fix. 

How can you repair a leaking double handle faucet with a compression valve?

What You Need:

• Small towel (optional)
• Screwdriver
• Wrench
• Replacement parts kit (optional)
• Replacement washer, o-ring, and/or valve seat (as needed)
• Plumber's grease

Step 1: Prepare the Sink

Turn off the water to the sink using the shut-off valve, which is usually attached to the pipes hidden in the cabinet under your sink. Make sure the shut-off valve is fully turned off; you can test this by turning the faucet handles both fully to the on position and checking for water. Leave the handles in the on position.

Plug the sink to avoid losing any screws or other small parts as you work. You can also place a small towel in the sink for added assurance.

Step 2: Access the Valve

Examine the tops of the handles to determine how the handles remove from the body. There will be either a pull-off cap or a screw. If your handles have the cap, use the edge of a screwdriver to gently pry the caps off and the handles should then simply twist off the body. If there's a screw on the top of the handles, remove the screw, set it aside, and then pull off the handle. Set the handles aside for safekeeping while you finish the project.

Note that if you know only the hot or water line is leaking then you only need to remove that handle. If both seem to be leaking or you are unsure, it is best to work on and repair both of the handles at the same time.

You should now see a valve stem sticking up from where the handle was located. Pull the valve stem out and turn it over to examine the bottom. There is a large metal washer topped with a rubber o-ring. Use a wrench to remove the washer and gently pull off the o-ring.

Lubricate the end of the valve with some plumber's grease. Replace both the washer and the o-ring using your parts kit or the individual parts you purchased.

Apply plumber's grease to stem of the valve then put on the new replacement washer and o-ring. Place the stem back in the hole making sure the washer and o-ring side is facing down.

Step 3: Test for Leaks

Reattach the handle covers, remove the towel from the sink, and turn the water supply back on. Test for leaks by either waiting to see if anything happens or turning both handles on briefly before turning the handles back off and waiting for drips.

Is the leak fixed? You are done with this project. Still leaking? You need to get back inside and replace the valve seat. Follow the same procedures to gain access from turning the water shut-off valve back off to opening the handle and seeing the valve.

Step 4: Replace the Valve Seat

Pull out the valve stem and look into the hole. You should see a column-shaped device inside. That's the valve seat and it simply lifts out. Replace the valve seat with a like model and then reassemble the faucet handle. Make sure you turn the water supply back on when you are finished.

Still leaking? Call a plumber by Plumbing Now for a diagnosis and the possible installation of a new faucet.