If one of your car's tires keeps losing air, then it is important that you determine the root cause of the problem. Since car tires can leak out air for a variety of reasons, finding the cause will allow you to have the problem repaired or your tire replaced if that becomes necessary.
You should never drive in a car with a tire losing air because the tire could blow out on the road and cause an accident.
Below is a list of each reason your car's tire could be losing air and how you can fix the problem:
The Tire has an Object Stuck in It
The first step in determining the problem with your car's leaky tire is to visually inspect it, looking for nails and screws. You may have run over some hardware on the road and may see the head of a screw or nail sticking out of the tire. If this is the case, then the tire can possibly be patched. Holes along the tread of the tire can be patched from the inside, but holes on the sidewall cannot be safely patched and your tire will need to be replaced.
The Tire Has a Hole in It
If your car's tire was cut or punctured, then it may have an area that is leaking air. You can find a hole in your tire by painting it with some soapy water and watching for bubbles where the air is escaping. You can also run your hand along the tire and feel for air leaking out. As with a tire that has something stuck in it, a cut or puncture can be repaired from the inside only if the hole is on the tread area of the tire. Otherwise, the tire will need to be replaced.
The Tire Has Lost Its Mounting Seal on the Rim
Sometimes a tire will lose a bit of the glue that holds it onto the rim. When this happens, air can escape out between the tire and the rim. If your car's tire is leaking from the rim, then you can take it to your local tire shop and they can take it off and remount it for you.
The Tire's Valve Stem Is Damaged
Finally, if your car's leaky tire does not have a puncture, embedded nail, or a leaking seal, then you should suspect the problem is with the valve stem. Feel around the valve stem and see if air is leaking out. If the valve stem has become damaged from road salt or age, then it can be easily replaced at your local tire shop.