Inspect the valve stem you just removed. At the very bottom, there will be a rubber seat washer held on by a brass screw. This is the most common cause of a spout drip. Use a flathead screwdriver to remove this screw and the old washer. Replace it with a new seat washer of the exact same size. Also, examine the O-ring(s) on the body of the stem. If they appear flattened, cracked, or brittle, they should be replaced. Pry the old O-ring off with a small pick or screwdriver and roll the new one into its groove. Before reinserting the stem, apply a small amount of plumber's grease to the new O-ring(s) and the stem threads to ensure a smooth operation and good seal.
Step 4/7
Replace the Seat Washer and O-Ring2 min