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The paperwork for the two new steer tires I just bought say to re-torque in 100 miles.

[John]

Roy,

At the very least do not drive on that tire unless if is vital. Advise anyone who works on your coach if you ran it at low pressure to not air it up, but to have it carefully inspected by a trained technician. Running a tire on low pressure with a 20% or greater loss of pressure is cause to remove it from service. If it was on a drive axle and you ran it low on pressure two tires may have been damaged, the one run on low pressure, and the one that carried more weight than the pressure was able to handle due to the low pressure in the other tire.

I am amazed the man who did the service call had the balls to air up the tire unless you just lost pressure while parked.

[Michael]

Jon,

I backed the coach out of the barn. Checked the tire pressure all were ok, or so I thought I checked all the tires. Drove about 10 miles about half at 40 mph or less about half not over 60 mph. Parked at a small RV park near my house. Checked the tires again and the passenger outside drive was at 27 psi. ( I guess I missed it at the barn) I aired it up using a 6 ft air hose standing 6 ft away standing besides the coach. A day later had lost 5-6 psi, called road service. Tire tech checked the tire for leaks, soapy solution, don’t know if he checked the insides. Did not check inside duel tire. What do you think, could I have damaged the inside tire?

Roy

[Deleted User]

You may not have. Running at low pressure which is what you did to both tires flexes the rubber and belts in a way they are not designed to handle. If you can imagine a thin strip of steel that you flex back and forth it will get warm where it is flexing and if you flex it enough it will eventually break where it is bent. That is what is happening to the steel belts that are in the tire. The flexing occurs near where the tread joins the sidewall.

When those belts heat from flexing they can reach a temperature that exceeds the temperature that the rubber can handle. So you have a double whammy because the bond between rubber and steel belts can be compromised and the steel belts can be weakened from the flexing to the point of failure like the metal strip I mentioned above.

In extreme cases the heat damage can be seen on the outside of the casing near the juncture of the tread and sidewall, but in less extreme cases the tire has to be removed from the wheel and the inner liner has to be examined. The inner liner is a gray color, but if it got sufficiently hot there will be a dark ring all around the tire and if that is seen the tire must be removed from service.

In your case both tires need to be examined. The failure of the tire if it occurs can happen at any time. We have a member whose tire failed while he was airing it up and he was seriously injured. It was an inner dual that failed and if it had been the outer tire he most likely would have perished. In some rare instances the tire will make a snapping or crackling noise prior to failure. Usually while it is being inflated. That noise is the steel belts around the sidewall breaking until they reach a point at which the tire explodes.

I don’t want to sound like the sky is falling, but the potential for injury as a result of a zipper failure is very high, and if you are lucky and it happens while you are driving you only get to experience a lot of damage to the coach.

Obviously driving slow on low pressure is going to minimize the heat build up, but if it happened to me I would have the tires carefully examined.

I will be a very cautious guy around my tires now that I have had the opportunity to take the seminar put on by Michelin. They take the potential for damage from your situation so seriously that before recapping or allowing a tire to go back into service they may even x-ray the tire to visually inspect the belts.

[Tim]

Thank you Jon, very good information. I will have the insides of the tires inspected.

Roy