Not every flat or damaged tire can be fixed. Sometimes, you just need to replace a flat or damaged tire. However, there are other instances when you can get the tire and your entire car back on the road with a quick tire repair.
When to Repair, When to Replace
Here, we’re going to steer you toward when you should get a tire repaired and when you should get it replaced.
- If you’ve got a tire that’s been punctured by a nail or another object, the tire can be fixed, but only as long as the puncture is in the tread area and doesn’t measure more than 1/4 of an inch in diameter.
- If the puncture is in the sidewall or shoulder of the tire, you’ve got to ditch the tire and get a new one. Safety first!
- If there’s more than one puncture, you likely can get the tire repaired if the punctures are at least 16 inches apart. Otherwise, it’s time to buy a new tire.
- If the tire has sustained serious damage in a crash, such as big cuts or tread separation, it should be replaced, not repaired. No ifs, and, or buts.
A tire can be repaired if:
- It is punctured within the puncture repair area of the tire (pictured under the “non-repairable tire” section below)
- The sidewall and the shoulder of a tire cannot be repaired per TIA and USTMA guidelines
- The puncture doesn’t measure more than 1/4 of an inch in diameter
- The repairs do not overlap or if the injuries are not directly across from each other
Tire Repair Process
- Remove tire from the rim
- Thorough inspection of both the inside and outside of the tire
- Although a tire may appear to be a simple fix from the outside, the bottom half of the nail could have caused potential damage to the interior sidewall
- Once deemed repairable, trim the puncture area of damaged cables to clean and stabilize the area
- From the inside out, pull a rubber stem through the puncture area sealing off the inside of the tire
- From the inside, buff the puncture area then apply special vulcanizing glue
- A patch is then installed on the inner liner over the puncture area causing a chemical reaction
- Tire is then mounted back on the rim, inflated to the proper tire pressure and the repair is checked for leaks
This procedure takes 60-90 minutes to be done properly.
In some cases, the tire can’t be repaired due to the location or severity of the damage. If the tire meets any of the non-repairable guidelines below, it’s time to buy a new tire.
1. Puncture Outside Repair Area
- If the tire is punctured in any way outside of the Puncture Repair Area, the tire cannot be repaired safely.
- True tire repairs are limited to the middle, or “crown” area of the tire.
- 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.
2. Size of 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.
3. Bulge or Bubble in 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 type of road hazards.
- The resulting bulge or “bubble” in the sidewall is not repairable, and unfortunately, the tire must be taken out of service.
4. Say “No” to Tire Plugs
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. Although the leak may stop, it is easy to believe that the tire is repaired and good to go; unfortunately, that’s not the case.
Tire plugs are a quick fix and can fail over time. They can also potentially cause air to become trapped between the layers of tread, eventually causing the tread to separate and result in needing to buy a new tire.
Industry Standards for Tire Repairs
The U.S. Tire Manufacturers Association (USTMA, formerly known as Rubber Manufacturers Association) and Tire Industry Association (TIA) standards:
USTMA Tire Repair Basics:
- 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 inner liner. 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.
TIA Tire Repair Basics:
- 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).