Poor connections and seals cause leaky faucets.
Old parts that have worn down and are no longer providing the proper seal generally cause leaky faucets. Repairing a leaky faucet involves knowing which type of faucet you have. Homeowners generally install compression or ball faucets in their bathrooms. Compression faucets have two handles that supply either hot or cold water while ball faucets have one handle that rotates on a ball to control the water's temperature. Turn off the water before working on the faucet to make the repair job less messy. Purchase replacement kits at home improvement or hardware stores.
Instructions
Compression Faucets
1. Remove the faucet handles by prying off the decorative caps and pulling off the handles. Set them aside.
2. Remove the packing nut by unscrewing it with a crescent wrench. Pull the stem out of the bottom of the packing nut and pull off the o-ring. Slip on the replacement o-ring.
3. Remove the seat washer and throw it away. The seat washer is the last component in the faucet and will either still be in the faucet casing or be jammed into the stem.
4. Put a new seat washer into the faucet.
5. Press the stem back into the packing nut and place it over the seat washer.
6. Slide the handle cover over the packing nut and press the decorative cap back into place.
Ball Faucets
7. Remove the handle by rotating it to reveal the screw and unscrewing it. The screw back may be covered by a screw cover that you can pry off with a flat-head screwdriver. Set the handle aside.
8. Pry off the cap along with the cam and packing rings. Set them aside.
9. Remove the ball, ball seats and springs and throw them away. The seats and springs help balance the ball and will cause a leak if they begin to wear down. The ball will also wear down over time and cause a leak.
10. Slide the replacement springs, seats and ball back into place.
11. Lay the packing and cam rings over the ball and push the cap back into place. Slide the handle over the cap and screw it into place. Replace the screw cover.