Before You Start
Ball-type Faucets

This type of faucet contains a lot of parts, and that often makes it difficult to find the cause of the leak. You can avoid the aggravation by buying a replacement kit and putting in all new parts. First, remove the handle set screw and lift off the handle. Use adjustable pliers to remove the cap and collar. Using the special tool included in the faucet-repair kit, loosen the faucet cam and lift it out along with the cam washer and the rotating ball. Reach into the faucet body with needle-nose pliers and remove the inlet seals and springs.
Next, cut off the O-rings, coat the new ones in nontoxic, heat-proof plumber’s grease and roll them on. Install new springs, valve seats and cam washers as you reassemble the faucet. Another more expensive option for an older faucet is to replace the entire fixture. You’ll need a basin wrench to do this.
Cartridge Faucets
Pry off the decorative cap on the handle, remove the handle screw, tilt the handle back and pull it off. If there’s a threaded retaining clip holding the cartridge in place, use needle-nose pliers to remove it, and then pull the cartridge straight up. Remove the spout and cut off the old O-rings using a utility knife. After coating the new O-rings with nontoxic, heat-proof plumber’s grease, reassemble the unit.
To replace the entire cartridge ($10 to $15), match the length of yours to the replacement cartridge length. Also match the stem end where the handle attaches.
Ceramic-Disk Faucets

Push the faucet handle back to access the set screw. Remove the screw and lift off the handle. Remove the escutcheon cap, unscrew the disk cylinder mounting screws and lift out the cylinder. With a blunt screwdriver, lift out the neoprene seals from the cylinder (if the seals are damaged, replace them) and use distilled white vinegar and a plastic scouring pad to clean the cylinder openings.
Rinse thoroughly. Then replace the seals and reassemble the faucet. Move the handle to the “on” position and very slowly turn the water back on—the force of the returning water can fracture the ceramic disk.
If you’re replacing the entire cylinder, which seldom is necessary, merely set it in place and secure it with the new mounting screws.