A ball faucet has a metal or plastic ball with grooves that control flow. Small springs press rubber seats against the ball. Replacing the seats and springs usually will stop a leak. However, the ball may also need to be replaced.
Tightening the adjusting ring with pliers or a special tool may stop a leak. If water flow is slow or erratic, remove the seats and springs and flush out any debris.
For more problematic leaks or issues, you may need to remove and replace several parts in your faucet. To relieve some of that stress, we have easy instructions below. This is a fairly quick project once you have the right parts and you should be done in an hour or two.