While almost any sharp object left on the road can cause a puncture, most are caused by small nails and screws which keeps them within the general guidelines which allow the repair of punctures in a tire's tread area of up to 1/4" in diameter. Repair of larger tread punctures and of punctures to the tire's shoulder and sidewall areas are not recommended.

There are three primary considerations when repairing a punctured tire. You need to evaluate the damage the object caused as it punctured the tire, reestablish an airtight seal of the tire's innerliner, and fill the path the object took through the tire. Often a "mushroom" shaped patch and plug combination repair is is used when repairing a punctured steel belted radial.

 
tire repair tools

Any repair done without removing the tire from the wheel is improper. Without inspecting the inside of the tire for hidden damage comes the risk of returning a weakened tire to service. Punctures in the tread area that looked repairable have revealed upon further investigation that the object that punctured the tire had been long enough to cut the tire's sidewall from the inside. Without dismounting the tire, the hidden damage would have been missed. Simply "plugging" a tire from the outside without removing the tire from the wheel is improper. (If a tire is punctured while off-roading far away from civilization and a spare tire isn't available, a plug may serve as a temporary low speed solution which must be replaced with a proper repair as soon as possible upon returning to the road.)

There are many different rubber compounds used in a tire. The tire's innerliner uses a special rubber compound that has the ability to better retain air. Once punctured, the innerliner must be cleaned, buffed, cemented, patched and coated to assure its ability to retain air has been restored. Since this can only be done from inside the tire, it's another reason that a "plug" only repair is improper.

Continuing to drive on a tire with a "slow" leak may allow moisture to seep around the object and into the tire. This will reduce the probability that the tire can be repaired properly because the moisture will ultimately reach the internal steel and fabric cords used to reinforce the tire and possibly cause rust and loss of strength.

As with most tire dealers, Hogan Tire uses the inside patch or inside plug method exclusively. Be aware that if a dealer or garage says that they can repair a tire in 10 minutes for under $10 dollars without removing it from the wheel, they aren't following the Rubber Manufacturer's Association procedures. A correctly done flat repair that follows the multi-step repair procedures will take approximately 30 minutes and cost around $20 depending on size. Driving on an improperly repaired tire is dangerous because it can further damage the tire and/or allow its strength to deteriorate over time. An improperly repaired tire driven at high speeds may suddenly fail, causing loss of vehicle control. Additionally, the use of an innertube as a substitute for a proper repair generates additional heat and should not be considered.