Looking to fix your faucet without hiring an expensive plumber? If your kitchen is fixed with some of the best touchless kitchen faucets then there are chances that you may not even need to get it repaired. With all three basic types- cartridge, valve, and ball- most manufacturers do their best to hide the screws and nuts that hold them together. Some are hidden under snap or screw caps on top of the handle; sometimes a nut is located at the base of the spout; or there may be a set screw located under the handle. On some cartridge types, you find the set screw by pushing the handle all the way back and looking under it.
Cartridge faucets come in two varieties: the metal sleeve with a screw holding it from the top and the newer ceramic disc.
Disassemble the metal sleeve style by rem
oving the screw, then pushing a screwdriver down the hole to keep the stem in place while you pull off the handle and cover. Then unscrew the retaining nut and remove the spout. With the faucet body exposed, you can see two O-rings- one at the top and one at the bottom. These are probably the source of your leak. Remove the retaining clip at the top of the faucet body, lift it off the stem, and replace the rings. Reassemble the faucet by putting everything back in reverse order.
To remove the ceramic disc cartridge, tilt the knob all the way back to expose the set screw, loosen the set screw, and lift the handle assembly free. Unscrew the screws on top of the brass collar beneath the handle assembly. Lift out the disc cartridge assembly and examine it for wear and cracks or other damage. If the ceramic disc is damaged, it will have to be replaced with an exact duplicate. If the machined surface on which the disc rides is damaged, it will have to be re-machined at a machine shop or the whole faucet will have to be replaced.
For valve faucets, unscrew the collar at the base of the spout and pull the collar and spout free. If your only problem is a leak around the base of the spout, replace the O-ring and reassemble the faucet. Otherwise, with the spout off, lift off the faucet body cover. When the escutcheon is removed, you will see a hexagonal plug on each side of the faucet. Beneath each plug will be a gasket, strainer, spring, stem, and valve. Under the valve will be a valve seat that will have to be removed with a hexagonal seat-removal tool. Remove all these parts and examine them for wear and damage. Take any parts that need replacement to your local dealer to be sure the new parts match, and then reassemble the faucet in reverse order.
Finally, for ball faucets, loosen the set screw at the base of the handle and lift off the handle. Wrap the screw cap beneath the handle with tape to protect its finish and unscrew it with a pair of channel-lock pliers. When you lift the ball-and-cam assembly out, you will be able to see two rubber valve seats underneath. If your faucet has been leaking, these valve seats are no doubt the problem. Pull them out with needle-nose pliers and replace them. If the ball is corroded or gouged, it will have to be replaced too. If not, slip it back into place. A slot in the side of the ball must line up with the metal projection on one side of the housing. The plastic cam assembly then slips on, its tab lining up with the slot in the faucet body. Before putting the handle back on, turn on the water and open the faucet. If there is a slight leak around the stem, tighten the adjusting ring inside the cam assembly by putting a screwdriver in the slot and turning the ring.