These instructions apply to almost all two handle faucets used in kitchens, bathroom, laundry room, and bar sinks. There are three major type of these faucets; seat-washer-stem, diaphragm, and washerless cartridge types. The seat-washer-stem is the most common and can usually be identified by turning the handle. If it turns more than completely around, then you probably have this type, which is usually the least expensive to repair. The other types generally only turn about one quarter of the way.
To re-washer the stem, remove the bib screw and pull the washer off. If the screw breaks, you will need to drill it out and re-tap the hole. We can do this for you if needed. Replace the seat washer with the correct size. You can usually read the size from the bottom of the old washer. NOTE: Almost every manafacturer supplies their stems with flat washers. Use of a beveled washer may cause the stem to wear out prematurely. Check the old washer for tears and nicks. If it's badly worn, you should replace the bib seat. Look down at the seat (you may need to remove the water with a paper towel) and inspect for nicks or cracks. If there are any at all, you should replace it. You will see on the inside of the seat a 4 or 5 sided hole. Using the correct seat wrench, unscrew the seat and replace with the correct new one. Very few faucets do not have removable seats. If the hole is round, it may not be replaceable and you will need a seat dresser to repair it. Bring in your stem to the store so they can check to see if your seat is not removable. If your local store has a box of seats with about 20 different sizes, it's time to leave. While a seat with the correct thread size will appear to work, you may soon need to replace the stem. Remember, your faucet was designed to use specific parts that work together. Using an incorrect seat has changed the way that the stem works and can lead to premature wear. Good suppliers carry over 200 different seats and can fit almost every faucet out there. Please bring your stem with you so they can look up the correct part.
While the stem is out, replace all packings, gaskets and "o" rings. Quality suppliers will stock the correct packings, gaskets and rings for your faucet. Bring your stem in so they can look up the correct parts for you. Again, remember, it's important to use the correct parts. Replace the stem and stem sleeve. Do not overtighten. Turn on the water and check for leaks.
Repairs for this type are the same as above except there is no screw on the bottom. Just pull off the diaphragm and replace. Be sure to also replace the "o" rings on the stem.
This is known as a washerless faucet, but as you will soon see, most do use a type of washer. The most common type is made by Delta/Peerless, Valley, and some imported clones. Following the above instructions, remove the cartridge and inspect the bottom for nicks or scratches. If nicked, it needs to be replaced. If not, look down into the hole that you took the cartridge from and at the bottom, you will see a black rubber piece. Pluck out this rubber seal and remove the spring below it also. Replace with the correct type. They all look about the same, so be sure to bring in the cartridge to get the correct match. Most other types of cartridges can not be rebuilt and must be replaced.