Any tire that chronically loses air, even small amounts, should be closely examined. Bits of glass, wire or nails embedded in the tread are obvious culprits, but the cause also could be a bent wheel rim, or a loose or defective valve stem (Schraeder-type valve stems screw in, so you can try tightening one on a leaking tire to see if it helps). Always use valve caps as a precaution.
You can also check a slow leak by removing the tire (mounted on its wheel), overfilling it slightly with air, then submerging it in a tub of water one section at a time. A thin stream of air bubbles will indicate a leak.
Regular tread inspections can also reveal uneven tread wear, which is usually caused by an out-of-balance wheel or front-end misalignment. Look for missing wheel-balancing weights (small dirty or discolored spots along the rim where the weights were installed).
Cracks in a tire’s sidewall indicate that the tire is old or its rubber compound has dried out. Tires that are not used regularly can actually deteriorate faster that those that see frequent use. Manufacturers recommend replacing tires when they reach a maximum of 10 years of age, although safety experts say tires that have been improperly stored or used can need replacement after only five or six years even if they are not worn out.
Driving on a flat tire or one seriously low on air for even a short distance will quickly ruin a conventional tire or render it unsafe for further use. If you ever find it necessary to do this, replace the tire instead of trying to patch or refill it with air. New run-flat tires have been developed to prevent loss of control in the event of a blowout. Most of these tires are designed to be repaired after run-flat use.
NEXT SEE: Car Tire Pressure & Care
—Michael Morris for HomeTips