Why do my tires keep losing air?

a1auto Maintenance, Repair

When you have a flat or under-inflated tire, the first thing you look for is a puncture or tear. But what do you do when your tires are not visibly damaged?There are two main reasons why tires lose air with no obvious injury: valve stem failure and mounting problems. Age, exposure to contaminants, and stress can cause these parts of your tire to fail.

Valve Stems

The valve stem is the mechanism that allows you to put air in a tire. It sticks out of the tire and can crack, become porous, or otherwise deteriorate. When this happens, air will slowly and constantly leak out of the tire.

Mounting Problems

Another location where air can escape is at the wheel rim, when the tire and wheel meet. Corrosion or oxidation can damage the seal between these two parts. The rim can also be dented, which can happen when you hit a pothole, curb or rock.

Temperature changes

A loss of tire pressure can also occur when the weather causes dramatic changes in temperature. Tire air pressure changes by one to two pounds for every 10 degrees in temperature change.

Effects of Under-inflation

When tires are under-inflated, it will cause them to wear more quickly, your fuel economy will suffer, and steering response will be inferior.

Finding the Leak

One process for finding the leak involves using a soapy liquid to reveal escaping air. You can also listen and feel for leaks.

Why do my tires wear so fast?

Fast-wearing tires can indicate that something else needs attention, such as alignment. Also, some cars are sold with soft-rubber tires that give an improved ride, but wear out more quickly. Compare the expected and actual mileage for these tires.