[HR9121]

Age shouldn't be an issue as stated above but what kind of hole is left on them? I ran one set until they completely went away one time and the run before was a dead hook then next pass just blowed the tire off. I've ran that tire anywhere from 16 to 28 psi with no issues.
If they are wore down bad it might be best just to replace them and see if you still have an issue. If you do, as Bill said you need to start checking for other issues.