Steady as she blows
Freightliner tractor with the Vigia Guardian external system installed.
How often do you check your tire pressures and pump them up? That is probably the single most critical factor in whether you can profit from using a tire inflation system. The more your tires run with improper pressure, the faster they wear and the more
likely you are to have downtime and service calls.
Many carriers are using inflation systems with good results, and it’s not just the big guys, either.
“We suffered from constant blowouts, underinflation, punctures and case damage,” writes Dennis Roohan of Farragher Logistics, an eight-truck fleet in New South Wales, Australia, in a letter to inflation system maker Vigia. “With the system, these problems were immediately rectified, and we have gradually seen an improvement in our tire wear and fuel economy.”
Harold Leiss, owner of Kirk National Lease in Sidney, Ohio, bought 50 Dana suspensions equipped with Dana Spicer’s inflation system in 2002. Since then, he reports no failures and noticeable improvement in tire wear, says James Beverly, a chief engineer with Dana. Leiss recently placed an order for 50 more systems.
Preventing tires from falling significantly below their rated pressure saves money in various ways:
FUEL CONSUMPTION. Less heat is generated by a fully inflated tire, so rolling resistance is much less.
TREAD WEAR. Low tire pressure, even 6 or 8 psi, means the tread doesn’t sit flat on the road; it also squirms and scrubs unnecessarily. Excessive flexing of the tread and sidewalls causes deterioration of cords and other tire materials. In effect, you are burning extra diesel to destroy your tires. In operations where tires are retreaded, not replaced, otherwise usable casings may be destroyed.
SERVICE CALLS. Many inflation systems not only counteract normal leakage but keep a tire with a significant leak properly inflated, allowing you to get home or to a service facility.
Vigia customer Walter Vicente, who owns and operates four-truck Vincent Lines of San Bernardino, Calif., saw this benefit when he tried to get a nasty puncture repaired while on the road, says Vigia executive Ken Siler. Vicente was told he would need a new tire for $350. He drove home to a familiar shop, where the tire was repaired for much less.
PARTS. By reducing heat at every wheel position, a tire inflation system can increase the life of brake linings, brake drums and wheel bearings.
INSURANCE. Inflation systems also can reduce the chance of a wheel-off, a potentially expensive and dangerous accident.
Inflation systems on the market vary widely in price and complexity. Many are designed to work only on trailers because in large fleets maintenance is much harder to track properly in trailers than in tractors.
All systems derive their air from the brakes rather than having their own compressor. For this reason, all have a protection valve to ensure that brake pressure is preserved in case of a significant tire or inflation system leak. Check valves ensure that one tire with a large leak will not deflate the others.
Some inflation systems have additional filtration to keep dirt and grit out of the valves.
With an effective and properly maintained brake air filter/dryer, there should be little or no debris in the brake air, anyway.