A leak in a tire is annoying and dangerous. Steel rims leak air through the rim and the tire, and alloy rims cause a leak through pores found in cast-aluminium alloy. The holes can be sealed and repaired, but replacing the rims or tires is recommended if the leak persists.
Inflate the tire to 18.1 Kilogram per square inch.
Demount the tire from the rim.
Place the damaged rim in a large tub of water and watch for bubbles indicating the origin of the leak.
Mark the leaks with a grease pencil and take the rim out of the water.
Sand the leaking areas with 80-grit sandpaper, then brush away any debris or remnants.
Dab the sanded leaks with a towel and clean the leaks with carburettor cleaner.
Cover the area thoroughly with a silicone gasket sealant.
Let the sealed rim dry overnight, then remount it onto the tire.