OEMs Expand Air Disc Brake Offerings; Cost, Maintenance Concerns Slow Adoption
After years of accounting for just a single-digit share of the heavy-truck brake market, air disc brakes are enjoying double-digit growth, and suppliers are optimistically predicting the systems will capture a quarter of the foundations brake market within a few years.
Supporters tout their durability, ease of service, lower maintenance costs and performance as advantages over drum brakes for over-the-road applications. However, disc brakes’ higher upfront cost — anywhere from $800 to $1,200 per axle more than drums — and some companies’ comfort with the simplicity and lower cost of drums remain high hurdles for broader adoption.
Nicole Oreskovic, product director of air disc brakes with Bendix Spicer Foundation Brakes, pins the current market adoption rate for ADBs among heavy trucks at about 13% but on the rise.
“We see that continuing to grow to [the] 20%-to-25% range over the next few years,” she said. “Overall, there’s been a compound 70% growth since 2005.”
Homer Hogg, manager of technical development with Petro/TA truck stops, said that while he did not have specific data, the number of ADBs they’re seeing at their shops around the country has been increasing.
“The total volume is not high relative to other brake work, but we definitely have seen more activity this year. It’s noticeable,” he said. Most of the work has been on trailers, Hogg noted, and most of that initially was related to the Department of Transportation, “making sure the calibrations were correct.”
Paola Carmona, program manager with Meritor Inc., also expects the market to rise from the current level of 14% that the company estimates.
“We see it growing to 24% by 2018. Partly as a result of the stopping distance regulations but also because fleets are getting more experience with them,” Carmona said.
There was some expectation that the reduced stopping-distance regulations enacted in 2011 and 2013 would drive increased sales of ADBs as some of their characteristics proponents tout — less fade and better heat dissipation compared with drums, for example — might make them a more attractive option for on-highway rigs. However, the larger drum brakes that companies such as Bendix, Meritor and others developed to meet the RSD requirements gave fleet managers a reason to stay with what they knew.
Instead, manufacturers have driven some of the increased adoption by making ADBs standard equipment on certain models.
The Paccar Inc. companies, Kenworth Truck and Peterbilt Motors, now offer disc brakes as standard equipment on the front axle of all Class 8 tractors and truck models. Peterbilt announced the change in the spring of 2011, and Kenworth followed two years later. Both use the Bendix ADB22x system.
Other OEMs said they are seeing increased interest. The use of ADBs on the Freightliner Cascadia model has risen 5% since 2010, said Mary Aufdemberg, director of product marketing. She attributed part of the growth to the industry’s focus on scoring under the Federal Motor Carrier Safety Administration’s Compliance, Safety, Accountability program, which monitors drivers’ and fleets’ safety performance.
“Compared to drum brakes, air disc brakes provide shorter stopping distance, better brake performance and are easier to maintain,” she said.
Jodi Presswood, vice president and general manager of Navistar International Corp.’s heavy-duty product line, said ADB penetration in Class 8s industrywide is reaching into the high teens. “While our penetration is a bit lower than the industry, we are seeing a significant increase in requests for air disc brakes that will get us up to the industry average soon,” he said.
Jeff Wittlinger, business unit director with Hendrickson Trailer Commercial Vehicle Systems, said his company is seeing 1% to 2% growth in ADB use annually, “but it’s very fleet-specific.”
And for some fleets, broad deployment of ADBs is still an open question.
Prime Inc., in Springfield, Missouri, doesn’t spec ADBs on its tractors because the company’s equipment turnover rates make payback on the investment difficult. However, the company is spec’ing them on 4,000 new flatbed, refrigerated and tanker trailers, said Paul Higgins, director of fleet maintenance. Prime’s goals are to reduce time in the shop and eliminate winter tire damage the company has been experiencing with drum brakes.
“When trailers sit for a while, moisture between the shoes and the drum freezes, and the tire locks up,” said Higgins, whose company ranks No. 21 on the Transport Topics Top 100 list of U.S. and Canadian for-hire carriers. “We’ve seen a lot of tire brake skids [in winter], and we suspect that ADBs are less susceptible to this because there’s less surface area between the pads and the rotor. ADBs are a pretty pricey upgrade, but we expect them to be in the shop a whole lot less often.”
Higgins added that they anticipate ADBs will give them three times the life of drum brakes.
Southeastern Freight Lines, based in Columbia, South Carolina and ranked No 28 on the TT for-hire list, never has spec’d disc brakes, but that could change as the company considers running some as a test, said Jim Boyd, manager of fleet technical services.
“There are a number of reasons we would want to run disc brakes in a limited test, evaluate these systems to determine if there may be reduced service times and/or costs, determine if we can obtain longer intervals between relining and, finally, determine if they contribute to an overall better solution to stopping tractor-trailer combinations,” he said. “We always look at new technology that we can possibly utilize that increases the efficiency of our fleet.
And disc brakes can improve efficiency in the service shop, said Bendix’s Oreskovic. Fleets can expect to save about 25% in maintenance costs with ADBs compared with drum brakes, she said. For example, changing out ADB pads can be done in less than 15 minutes with wheels off compared with 60 minutes for a drum brake, and rotors should last [two to three] pad changes, depending on application, she said.
Plus, Oreskovic noted that fleets can carry significantly fewer service parts in inventory compared with vehicles with drum brakes. Steer, drive and trailer Bendix disc brakes can be maintained with an interchangeable service kit for brake pad, rotor, tappet boot and guide pin boots, she said.
“It’s difficult to say what the specific annual budget would be as that depends on the fleet’s setup, but they should see a reduction in their inventory costs,” Oreskovic said.
And training technicians to service ADBs is relatively simple, said Jeremy Fox, technical training manager at Meritor. Technicians can service and maintain ADBs “with very little training compared with pneumatic drum brakes.” Meritor offers four Web-based courses that cover what techs need to know, he said.
Petro/TA’s Hogg said that inventorying the 235 shops nationwide to handle increased ADB work is an issue his company must address. “There are such a wide variety of applications, brands, styles, etc. . . so stocking is a challenge. We’re stocking the top one, two and three items.
To date, ADBs are mostly application-specific. Waste haulers use them in their heavy stop-and-go operations. Tank truck fleets can translate the ADBs’ lighter weight — about 100 pounds per tandem — along with other weight-saving components into revenue-producing cargo, Hendrickson Trailer’s Wittlinger said.
Hendrickson, in fact, launched an ADB system for trailers this spring. The Maxx22t combines Hendrickson technology with an air brake system supplied by Wabco. The system is optimized for North American trailer applications, Wittlinger said. The package adds about $700 to $1,000 per axle, depending on the options, the company said at the launch.
And that kind of financial premium is proving prohibitive for some companies.
At First Fleet, a contract carrier based in Murfreesboro, Tennessee, the cost/value calculations with ADBs “just don’t work”, said Allen Caldwell, manager of maintenance technology. “There’s a significant upcharge for air disc brakes — $2,000 was the last quote — and at the end of the truck’s life, we’re not getting what we think is a good residual value,” he said. “They’re just not a feasible option.”
ADBs “are not for everyone,” said Joseph Kay, director of North America brake engineering for Meritor. “They don’t fare well in a dirty environment, on dirt roads, because they pick up materials and get more abrasion between the pad and the rotor.”
And despite the recent industrywide increases, ADBs still are spec’d on fewer than 2% of Wabash National trailers, said Robert Lane, director of business de¬velopment with Wabash National. “Historically, we range between 0.2% and 2%, with little deviation,” he said.
There’s a stronger market for ADBs in Canada, said David Grant, marketing director with Great Dane Trailers. “In the U.S., less than 2% of our new trailer orders specify disc brakes. In Canada, however, the percentage is much higher . . . closer to 10%.
“We’ve seen in¬creasing interest in disc brakes recently in all of our markets,” Grant said. “However, this hasn’t translated into a significant increase in disc brake orders yet. We do expect orders for disc brakes to increase in the coming years but can’t quantify that increased demand at this time.”
