We all know that brakes wear out. They are actually made to wear out. That is how they perform their function. But that does not mean you as a person who maintains trucks or buses would mind seeing them last just a little longer and perform just little better.
Michael Caggiano of Bendix Brakes says the goal of brake manufacturers is to get brakes to last longer without compromising their effectiveness. That means finding materials that will help the brakes perform their job with less damage, wear and tear. “To be quite honest, no one’s completely there yet,” he says.
Unlike engines and other truck components, Caggiano points out, brakes often come last from an innovation standpoint. “It is essentially the same brake today as it was in 1940,” he says. Yet everything else has changed, all the other dynamics from traffic to truck size. Trucks are performing in extremely different environments than in the past. Need proof? On many downhill grades, drivers today often have to rely on their brakes instead of downshifting.
In order to gain better fuel economy, modern H.D. vehicles have less rolling resistance and wind resistance, thanks to radial tires, aerodynamic designs, high-speed rear axle ratios, and less drag inside the engine. This adds up to a 30% decrease in the vehicle’s natural retardation versus 15 years ago, and the brakes have to take up the slack. So while engines and other truck components have progressed so that they need less maintenance than ever before, brakes are taking more abuse while their make-up remains only slightly changed.
What innovations will help bridge the gap between the brakes and the increasingly brutal environment they are expected to perform in? Caggiano says next to advances in friction materials, air disc brakes will help change the landscape of heavy-duty braking. Air disc brakes provide shorter stopping distances and are lighter and easier to maintain than drums, though their linings do not necessarily last longer. Already being used in Europe, Caggiano thinks other areas of the world will also see the proliferation of air disc brakes. However, he says it is going to take government action and changes to stopping distance requirements before air disc brakes become common because it is an expensive changeover.
Dennis Henson with Dana/Spicer’s Heavy Duty Axle and Brake Division, says the heavy– duty brake industry will continue to see wider brake packages and evolving brake linings. He believes wider brakes will offer fleets many benefits, such as reduced operating costs per kilometer or mile. As for linings, he says, “The challenge is, can you get them to wear longer?”
Spicer has several products available to help meet that challenge. The Class 7 and 8 Air Disc Brake System features easy-access quick-change linings to minimize maintenance labor and expense. Dana’s LMS brake package is available in both “low lube” and “lube free” versions to eliminate brake and automatic slack mechanism lubrication. “Low lube” versions increases brake and automatic slack lube intervals to 400,000 km (250,000 miles). The “Lube Free” version makes this traditional maintenance procedure entirely unnecessary. This has the potential of eliminating brake maintenance altogether for fleets that “turn” their vehicles every three years. Henson says the technology goes towards having the product serviced only when there are issues in it.
It is not easy for the brake manufacturers to keep up with all the developments affecting the world of heavyduty vehicles, however. “Every time you think you see the target, they. move it just a little bit,” Caggiano says. Whether because of emissions regulations, economic factors, or fuel availability and price, the brake industry sees a variety of changes it is forced to deal with.
Service issues are no different. Caggiano sees the biggest issue as a lack of good technicians. “The industry in general, not just brakes, needs warm bodies,” he says. With the rapid growth in the truck population, there is now a shortage of both service repair facilities and technicians capable of handling today’s complicated trucks. Regardless of how much training is done, technicians with solid experience are still needed. “You just cannot teach experience,” Caggiano says. “Jobs that should only take an hour and a half are taking five and a half hours.” He also mentions that brake repairs still require some basic hands-on work, grease and all, so many technicians do not want to do the job, preferring instead higher-tech work on other systems.
As for the future of heavy-duty brake service, Henson says it will be “smart” brakes with sensors that will have the ability to monitor lining wear and tear and provide an indication of when maintenance is needed. Caggiano agrees, saying brakes will become more technologically advanced, similar to engines. “It is on the horizon,” he says.
Why has the evolution of the brake industry lagged behind that of other systems, such as engines? Caggiano says it is because brakes have always been simple and dependable – you step on the pedal and they stop the vehicle. “It is not very glamorous,” he says.
Still, the brake industry continues to grow. For example, Dana Corporation is expanding, especially throughout Europe, having recently announced plans for a state-of-the– art technology center for research and development in Pamploma, Spain. “The European Heavy Axle and Brake Technology Center plays a key role in enabling Dana to provide value-added solutions to our customers – all over the world. We are dedicated to providing technologically– advanced, high-quality products that meet the needs of today’s European OEMs,” says Josetxo Zugalidia, general manager of Dana’s Heavy Axle and Brake division. Dana currently has 17 advanced technology centers located throughout Europe.
Park, Jocelyn (2001). Heavy duty brakes 2001. Auto & Truck International, 78(2), 26.