The ins and outs of truck tire repair

In many ways, the rules regarding truck tire repair are black and white. In other ways, truck tire repair is best defined as shades of gray. Here is the difference between fixing and repairing a tire.

There’s a huge difference between fix and repair. Just do a Google image search for “there, I fixed it” to get a better understanding of what I’m saying. Some segments of the truck tire industry have an admittedly earned reputation of fixing flats instead of repairing tires. Fixing a flat is easy. Just find the hole in the innerliner of a tubeless truck tire and stop the leak. In most cases, the fixer will use a patch. They may even take the time to buff the innerliner and apply a special cement to get vulcanization, which creates a molecular bond between the patch and the tire so it will hold air. And how long it holds air depends on a number of factors.  

Many years ago, I knew a young truck tire technician who could get just about anything to hold air. He would install a large repair unit on the inside of a sidewall and even install a small patch on the outside to cover the hole. A perfectionist, he would use black boot cement to paint the patch on the outside and then mount it on the rim so it was all the way on the inside and virtually undetectable to enforcement officials. His boss would just write ‘no guaranty’ on the ticket, and the customer was fine with taking a chance on a $50 fix when the other option was a new tire.  

While times have changed, the practice of fixing tires has not. It may not go to the extreme of the well-intended efforts of a young man who was just trying to help out his customers, but the risks that accompany a flat repair in present time are significantly greater than they were in the past because in most cases, it’s easy to prove that a tire was improperly repaired.  

In many ways, the rules regarding truck tire repair are black and white. There is universal agreement on the plug and patch approach as long as the injury is in the crown area of the tread and not larger than 3/8 inches. If the injury is in the shoulder, it can be repaired in the field when the diameter is 5/16 inches or less. An injury larger than 3/8 in the crown, 5/16 in the shoulder, or located on the sidewall must be referred to a full service tire repair facility for a section repair.  

A section repair requires a higher level of skill to remove the damaged rubber and steel cord material before filling the void with rubber and reinforcing the entire area with a larger repair unit. The maximum repairable injury size is determined by the size of the tire, the location of the injury, and other factors. 

Steer tire puncture repairs are not illegal. In a 1995 letter from the Federal Highway Association, the Office of Motor Carrier Research and Standards stated, “A nail hole repaired by using self-curing compounds or precured rubber inserts or stems, with a repair unit on the inside of the tire, is not prohibited by Section 10(a)(10) of Appendix G.” I still have a copy of the letter and use it regularly to prove my point. It is not against the law to install a puncture repair in a steer tire. 

It is, however, illegal to operate a steer tire with a section repair. While the definition of “boot, blowout patch, or other ply repair” in Section 10(a)(10) of Appendix G to Subchapter B is not clearly articulated anywhere to my knowledge, it’s safe to assume that all of these terms could be applied to a section repair. Therefore, it is against the law to operate a tire on the steer axle of any commercial motor vehicle if a section repair has been installed. 

Regardless, some fleets have decided to limit or prohibit repairing a tire on the front axle of a truck. As a policy, it is a very conservative approach to truck tire service, which probably has a lot to do with the ways that steer tires have been “fixed” over the years. If every commercial tire service provider followed the industry guidelines for tire repair, those fleets might be more willing to accept puncture repairs in a steer tire, but that’s not the case, so they don’t.  

Outside of those areas, truck tire repair is best defined as shades of gray. What is the maximum number of puncture repairs? It depends. What is the maximum number of section repairs? It depends. In either case, it is acceptable to install more than one puncture or section repair in a truck tire. According to the U.S. Tire Manufacturers Association (USTMA), however, “The number of repairs should be limited first by the tire manufacturer’s recommendations and repair policies. The condition and application of the tire should also be considered. … Tire manufacturers may have additional limitations on the quantity or location of section repairs.”  

Without industry consensus from USTMA on the maximum number of puncture or section repairs, fleets should make sure that their tire repair policies are in line with those of their tire manufacturers or these shades of gray could become the black and white of a lawsuit.    

Source: http://www.trucker.com