Repairing leaky faucets can be done by a home owner with only a few simple tools and some replacement parts. The parts you need will depend on the type of faucet you have and which part of your valve assembly is giving you a problem.
First you should check where the leak is coming from.
Is the water passing through the faucet or is it leaking from the handle.
If the water is flowing through the spout of the faucet and leaking because you just can not turn it off then you probably have a problem with your cartridge or valve.
If the water is coming out of the handle and the water that exits the spout can be stopped then you probably have a damaged o-ring or washer that seals the valve.
If you find you are leaking water from behind the wall of your bathtub faucet then you may need to remove a portion of your drywall to access the valve assembly. This could require a professional to help.
BEFORE YOU BEGIN
Make sure you can turn the water off to the bathtub or shower. If you do not have a valve in your basement that can control just that section or fixture of your plumbing then you will need to shut your water off at your service main valve. To make life happier make sure everyone knows and has had time to use whatever water needed before you shut off the whole house.
Most new bathtub faucets will come in a cartridge design.
This type of valve is very easy to replace when it causes you trouble but can be more expensive then older models that use washers.
An easy way to know if you have a cartridge based faucet is if you only have one adjustment valve for both hot and cold water.
There are variations on the design where a disk system is used but for the most part if a cartridge based faucet is leaking there are 2 possible problems and fixes.
If it is leaking from the handle then you need to replace the O-Rings and if it is leaking through the spout then you replace the cartridge. There are no available or reparable parts inside a Cartridge so you just replace the whole part.
Valve Stem Type
Older and even some new faucets will use a valve stem compression method to control the water in your faucet. If you have 2 handles there is a possibility that you have valve stems or your manufacturer may have just used two cartridges to control the hot and cold water independently.
Valve Stems can be replaced if they go bad but because they are made of brass it will take many years before they wear out.
On a compression valve stem as you can see here on one end there is a shaft that extends into and mounts the handle so you can turn the valve.
When you turn the valve the other end of the valve stem will bottom out inside the housing of the valve assembly or diverter. Because the valve is brass and so is the housing that it is inserted into you need a rubber washer on the end of the valve to make a tight seal.
When you turn it to the right the valve compresses a rubber washer at the bottom of the valve to stop the flow of water.
This is where the problem usually is in a Valve Stem Assembly.
Simply remove the valve stem and bring it to your plumbing supply house. They will have a wall of replacement seat washers for your valve for just a few dollars.
If you find you need to replace the whole valve then you simply provide the model and a replacement valve will cost you about $20.
If you are working on a very old model there are knockoff generic type valves that you can purchase for much older faucets.
Ball Type Valves
The final type of valve you may come into contact with is a ball valve. Ball valves are commonly used in kitchen sinks where you can rock back the handle and twist it left to right and up and down to adjust the flow of hot and cold water at the same time.
Ball valves are repairable and you will probably be able to find replacement parts for your faucet at your local plumbing supply house.
Ball valves have 4 basic parts. The ball with a shaft that extends out to the handle of the faucet. The socket that the ball fits into which is mounted in your diverter assembly. A spring and seat to allow the valve to work freely while providing the flow of water.
If you have a leak through the spout of a ball valve system many professionals would suggest that you replace the whole diverter valve system. This is an expensive propasition and will require access to the wall.
Note About Tools
Using the appropriate tools when repairing your valves is important. For the most part you will need either a screwdriver or hex wrench to remove the handle from the valve stem.
Fixed sized wrenches should always be used when removing the stem or its retaining nut. Do not rely on an adjustable wrench and never use pliers or you will destroy the soft brass metal faster then you can call your local plumber to rip your wall open to fix your mistake.
Stem seat conditioners that will grind the inside brass seat of your valve stem assembly while it is in the wall are available. Remember if you need to use this tool be very gentle or you will be opening your wall to replace parts.
If you ever replace your shower, tub or the surround and your valves are more then 10 years old you should replace the whole system. The small cost at that time will be well worth it.
The YouRepair Store
Carries a full line of repair parts, tools and replacement fixtures for your bathroom.