Remember the nearly daily news stories about tire blowouts on SUVs and the accompanying finger-pointing trying to pin the cause of failure on the tire or vehicle manufacturer? Well, the dust has settled and NHTSA has mandated the use of tire pressure monitoring devices on new vehicles equipped with passenger tires.
With a plan for light-duty consumer vehicles in place, the focus has turned to trucks. Although no official NPRM has yet been published, the information-gathering phase has begun. Truck operators must understand that pressure monitoring will be mandatory, and that the clock is ticking. So it makes good business sense to look at the many different options available for monitoring tire inflation pressures.
A good start may be to ponder several questions. For example, should the devices or systems adopted for trucks merely monitor inflation pressures and give an audible/visual warning to drivers if one tire falls below a preset threshold? An alternative approach would be to have electronic systems capable of replacing current maintenance practices of manual pressure checks through valve stems, an expensive and cumbersome process.
Currently available technology allows individual tire sensors to be read by hand-held data gathering devices at scheduled stops, and gate readers could be fitted at entry/exit lanes from yards, or at fuel islands. From a hardware standpoint, this would require sensors capable of “reading” actual pressures, rather than just triggering an exception signal when a low threshold is reached. With variations in target inflations used to address differences in equipment, operating conditions, and even axle-specific inflation tuning, such intelligent sensors may be a logical solution that could be cost-justified by reduced labor, improved inflation maintenance, and reduced unscheduled downtime.
Other options to consider include on-board inflation maintenance. These range from the relatively simple systems that use brake system compressed air to maintain a predetermined inflation level in trailer tires, to more elaborate (and expensive) total vehicle systems used to lower and raise pressures en route. A significant maintenance concern is that these systems normally do not alert the driver or technician to slow leaks. Casing damage/tire failure can occur if nail punctures, valve grommet leaks, or other such conditions are not detected and repaired.
Some maintenance executives think that the ultimate monitoring system would sense low inflation by axle-end position and send a warning to the driver, while concurrently forwarding this information to the maintenance shop via a GPS-based truck management system data link.
Other issues include the physical location and complexity of pressure sensors. Many would like the sensor to be attached to the tire interior and to include a temperature monitor or “tattle tale” feature, allowing ID of casings that exceeded defined temperature thresholds. When combined with current inspection techniques, this would facilitate accurate and consistent screening of casings to ensure optimum retread type and axle position selection.
There seems to be a consensus that tire inflation-monitoring systems for trucks should be designed to deliver more than a simple driver warning or exception report. They should also function as efficient tools to improve the routine maintenance of target inflation pressures.
