Proper Tire Repair
If your tire has a leak from a puncture, it is very important have it repaired properly.
At Sullivan Tire and Auto Service we abide by the Tire Industry Association (TIA) and U.S. Tire Manufacturers Association (USTMA, formerly known as Rubber Manufacturer’s Association or RMA) recommendations to properly repair a tire.
The first thing a technician will do, is determine if the puncture is within the repairable area of the tread.
The puncture must be within this area or it cannot safely be repaired. If it is within this area, the technician can proceed with the repair process.
Repairing a tire properly is not a simple procedure. The tire needs to be removed from the rim, thoroughly inspected by a qualified tire technician, and repaired from the inside using a proper patch/plug device. The puncture needs to be cleaned and buffed using specialized equipment. The patch/plug device is inserted into the puncture, pulled completely through the tire, and sealed using a special vulcanizing glue. The tire is then mounted back on the wheel, inflated to the proper tire pressure and the repair is checked for leaks. The tire and wheel assembly are then re-balanced and installed back on the vehicle.
This procedure takes 60-90 minutes to be done properly.
The proper device to repair a tire looks something like a mushroom. This device both patches and fills the puncture and is considered the safest way to repair a tire. The use of a patch or a plug alone is not considered a proper tire repair. At Sullivan Tire and Auto Service we ALWAYS use the patch/plug device when repairing a tire.
In some cases, the tire can't be repaired. Below are some of the reasons why.
Puncture Outside Repair Area
As stated previously (image above), if a puncture from a nail or other objects is outside of the puncture repair area, the tire can't be repaired safely.
The repairs are limited to the middle, or "crown" area of the tire only. The crown is defined as the center of the tread, approximately 1 to 1.5 inches in from each shoulder. For most tires, the puncture repair area can also be defined by the first major groove on both shoulders.
A tire's belt package provides strength and rigidity to the tread area of a tire, and is the only part of the tire that can accept a repair.
Size of the Puncture
The maximum repairable injury size for passenger and light truck tires through load range E is 1/4 inch, or 6mm in diameter. If the puncture in your tire is larger than the allowable repair size, the tire must be taken out of service.
Bulge or Bubble in the Sidewall
If there is a noticeable bubble in the sidewall of the tire, it has been damaged most likely by impacting a curb, pothole, or other types of road hazards. The resulting bulge or "bubble" in the sidewall is not repairable, and unfortunately, the tire must be taken out of service.
Impact Break/Road Hazard
The sidewall of the tire has ruptures or been cut due to an impact with a curb, pothole, or another type of road hazard. This type of injury is not repairable, and unfortunately, the tire must be taken out of service.
Examples of impact breaks below.
A tire that has been run under-inflated for an extended period rendering it not safe to be repaired and put back into service. This may only be evident after the tire is removed from the rim during the initial inspection part of the procedure.
Tire Plug vs. Repair
Although there may be a shop up the street that will plug a damaged tire for you, Sullivan Tire and Auto Service does not plug tires based on the USTMA and TIA safety standards. What is the difference between plugging a tire and repairing a tire?
A tire plug is a sticky, expandable object that gets pushed into the damaged area of the tire from the outside and is adjusted until the air is no longer leaking from the tire. Tire plugs do not require the tire to be removed from the vehicle and typically take 15 minutes to insert. Although the leak may stop, it is easy to believe that the tire is repaired and good to go but unfortunately, that's not the case. It is a temporary fix if you have a flat tire and need to get somewhere quickly but by using a tire plug, there is a possibility that the tire will need to be scrapped once it is inspected by a certified technician attempting to perform a proper tire repair. It will depend on the severity of the repair and the state in which the plug was applied. As your vehicle begins to travel on the road, your tires create friction with the road which then creates heat and eventually causes your tires to expand from the heat. When the rubber compound of your tires begins to expand, it will not expand at the same rate as the tire plug because they are made of different materials. The expansion of the tire when it heats up or the contraction of the tire when it cools down can potentially cause the tire plug to fail.
Plugging a tire from the outside can also cause air to become trapped between the layers of the tread. As the tire heats up the air between the tread layers of the tire also begin to heat up causing the air to expand. Since the air has no place to go, it will expand and push on the tread eventually causing it to separate from the rest of the tire. If the tire was properly repaired from the inside with a stem and a patch (see explanation below), the air from the tire would have nowhere to escape.
Tire Repair Patch and Stem
A tire repair patch and stem are installed when a tire is removed from the rim of vehicle. From the inside out, the repair stem is inserted into the hole followed by the patch being placed and adhered over the stem and damaged area of the tire. As stated before, a tire can only be repaired if the damage is not too severe and if the damage in within the tread area only. Until the tire is taken off of the rim of the vehicle, it is hard to tell if there is any additional damage to the tire that also may need repair or indicate if the tire is no longer salvageable. Repair patches are specifically designed to eventually mold themselves into the tire and become one with the tire rubber as the tire heats up. When the tire is reinstalled on the rim and air is added to the tire, it creates pressure which doesn't allow air to escape the tire. Unlike a temporary plug, a repair stem and patch ensure that your tire will not lose air and give you peace of mind that your tire is safe to drive on.
- Repairs cannot overlap. A rubber stem, or plug, must be applied to fill the puncture injury and a patch must be applied to seal the innerliner. A common repair unit is a one-piece combination unit with a stem and patch.
- Not all tires can be repaired. Specific repair limits should be based on recommendations or repair policy of the tire manufacturer and/or type of tire service.
- NEVER repair a tire that has an existing, improper repair; the tire must be scrapped.
- A plug by itself or a patch by itself is an unacceptable repair.
- NEVER perform an outside-in tire repair or on-the-wheel repair.
- The only way to properly repair a tire is to demount it from the rim so it can inspected on the inside, remove the damaged material, fill the void with rubber, and seal the innerliner with a repair unit.
- A plug by itself or a patch by itself is not an acceptable repair because the plug does not permanently seal the innerliner and the patch does not fill the void left by the penetrating object, which allows water to enter the body of the tire and starting corroding the steel belts.
- The use of sealants or emergency inflators that contain a sealant are not recommended as long-term solutions to a flat tire for the same reasons.
- Puncture repairs are limited to the center of the tread area. If there are punctures or damage in the shoulder or sidewall of the tire, it is not repairable.
- If the injuries are close enough so that the repairs overlap or the injuries are directly across from each other, the tire cannot be repaired and must be scrapped.
- Never repair tires with a tread puncture larger that ¼-inch (6mm).
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