Caution: Do not mix different types of tires on the same vehicle such as radial, bias, and bias-belted tires except in emergencies because vehicle handling may be seriously affected and may result in loss of control and possible serious injury.

Inspect the valve stem cores for leakage. Inspect around the tires for embedded steel, rock, or glass. In some cases the tube of an inflated tire may already be punctured, and pressure will be lost only when the object is removed.

Overloading is the cause of many kinds of cord body breaks. Such breaks are due to abnormal flexing or overworking of the cord body of the tire. Overload flex breaks occur in the sidewall or the shoulder of a tire. These breaks run with the circumference of the tire. Sometimes the breaks are only 51-76 mm (2-3 in) long. Other times the breaks will extend partly around the tire, resulting either in a blowout or a pinched tube that allows the tire to go flat.

Normal flexing of a tire can go on for long periods of time without causing any great damage to the cords. If the tire is overworked or overflexed from overload, then abnormal heat is generated, and the cords become weak and the cords break.

Underinflation will cause the same result. In addition, spring axles, mismatched duals, and poor load distribution tend to cause flex breaks. This can be avoided if vehicles are equipped with the tires and the rims of the proper size and type, large enough to carry the load. Inflating the tire beyond the maximum recommended pressure will not increase the rated carrying capacity of a tire. Refer to the manufacturer's specifications for load and pressure recommendations.