Repairing Leaky Faucets
The biggest problem with fixing leaky faucets is identifying which type of faucet you're working with. There are four basic types — compression, ball, cartridge, and disk — but endless variations. Even if you think you've figured yours out, it's best to take the faucet apart before heading to the home center for the replacement part. Take the old parts with you so that finding the exact replacement won't be a guessing game.
For all faucet repairs, first shut off the water supply to the faucet, either at the shutoff valve or at the house supply. Open the faucet to drain the water. Put the plug in the sink, and line the sink with a towel to protect it. Wrap pliers with masking tape to avoid scratching faucet surfaces. As you remove faucet parts, examine them to see how they're seated within the faucet, and lay them out on a paper towel in the order you removed them.
Compression faucets have two handles that twist on and off to control the flow of water. These older-style faucets, which include valve-type faucets often found in utility rooms, contain washers that often need to be replaced.
Remove the cap from the handle so that you can undo the screw holding the handle in place. The handle should lift off, but it's often seized. If so, use a tool called a handle puller that fits over the handle and applies pressure using a screw-down handle.
Use groove-joint pliers to remove the stem assembly from the faucet. To access the O-ring and the stem washer for replacement, take the stem assembly apart: Remove the stem screw, and unscrew the retaining nut from the spindle. Replace the O-ring (the old one can be cut off with a utility knife), stem washer, and stem screw, coating the new items with plumber's heatproof grease. Sometimes, you'll find packing string instead of an O-ring; in that case, wind new packing string in its place.
Before reassembling the faucet, check the valve seat. If it feels rough, use a seat wrench to remove it and replace it with a new one. If it can't be removed (some can't), smooth it instead by rotating a valve seat cutter (available at home centers) clockwise within the seat for several turns.
For a dripping faucet, try a quick fix by tightening the faucet cap with groove-joint pliers. If this doesn't work, the culprit is probably the ball, valve seats, or springs. For leaks around the base, replace the O-rings. Frankly, once you have the faucet apart, it's easy (and not expensive) to replace all of these items at once.
Use an Allen wrench to undo the setscrew on the handle, and take off the handle. Use groove-joint pliers to unscrew the faucet cap. You'll see the stem of the ball sticking up through the cam and cam washer. Remove the cam and washer, and then the ball. If the ball is worn, buy a new metal one (longer lasting than plastic). With the ball removed, the valve seats and springs are accessible. Pry them out with a small screwdriver or awl.
Lift off the spout (you may need to twist it while pulling up). Cut off the old O-rings with a utility knife and install new ones, first coating the new ones with plumber's heatproof grease. Reassemble the faucet with new valve seats, springs, and cam washer. When you're placing the cam in position, look for the slot on the faucet that matches the tab on the cam. Turn the faucet on, and then restore the water supply slowly to check for leaks. If leaks occur, reseat the ball and tighten the faucet cap and screw as needed (don't overtighten).
Ball faucets are easy to identify, because the handle rotates around a dome-shaped faucet cap to control both water flow and temperature.
Replace the O-rings to fix leaks at the base of a cartridge faucet; replace the cartridge to fix dripping spouts. First, pry up the access cap so that you can remove the screw in the handle, and then the handle. If there's no access cap, look for a clip and an Allen screw on the handle; remove both.
Cartridge faucets may have one or two handles that move up and down control the water flow.
Use groove-joint pliers to remove the retaining nut or ring combination, holding steady the assembly below it with an adjustable wrench. Look for a retaining clip, which may or may not be holding the cartridge in place, and note the position of the cartridge. Carefully pull the cartridge straight up and out, using groove-joint pliers. Buy a replacement cartridge to match, and insert it in the same position.
At this point, to replace the O-rings at the base of the faucet, lift the spout up and off. Cut off the old O-rings with a utility knife. Replace them, first coating the new O-rings with plumber's heatproof grease. Replace each piece of the faucet, and turn on the water slowly to check for leaks. If leaks occur, go back and tighten the nuts and screws slightly (don't overtighten).
Disk faucets rarely need repair, and when they do, it's usually to clean or replace their neoprene seals or to clean the openings in their ceramic disks. First, remove the setscrew in the handle so that you can lift off the handle and the escutcheon cap. This allows you to unscrew the mounting screws and lift out the cylinder that contains the ceramic disks; make sure to note the cylinder position so that you can replace it the same way. Pry out the neoprene seals from the openings in the disks, being careful not to scratch the disks.
Clean the seals, the disk openings, and the water inlets in the faucet body with a dish scrubber that's safe for ceramic surfaces (i.e., not steel wool). Reassemble the faucet, and turn it to its “on” position. Because the disks can crack if water surges against them too suddenly, turn on the water supply very slowly. If the faucet's still leaking, install a new cylinder, again noting the position of the old cylinder so that you can match it.
Disk faucets have a single handle that moves up and down to control water flow.