TL* THE CONTACT OWNS A 2009 JEEP WRANGLER. THE CONTACT STATED THAT WHILE DRIVING APPROXIMATELY 50 MPH THE TIRE PRESSURE LIGHT ILLUMINATED ON THE INSTRUMENT PANEL. THE CONTACT NOTICED THE REAR PASSENGER SIDE TIRE WAS DEFLATED. THE CONTACT REPLACED THE TIRE WITH THE SPARE TIRE. THE VEHICLE WAS TAKEN TO AN INDEPENDENT MECHANIC WHO DIAGNOSE THAT THE VALVE STEM HAD FRACTURED CAUSING THE TIRE TO LOOSE AIR PRESSURE. THE MECHANIC REPLACED THE VALVE STEM. THE VALVE STEM ON THE SPARE TIRE WAS ALSO REPLACED WITH A RUBBER VALVE STEM. THE CONTACT NOTICED THE VALVE STEM ON THE FRONT AND REAR DRIVER SIDE AND THE FRONT PASSENGER SIDE TIRES WERE ALSO CRACKING. THE VEHICLE WAS NOT REPAIRED. THE APPROXIMATE FAILURE MILEAGE WAS 30,000.