OEMs Promote Disc Brakes as 2007 Option
By Frederick Kiel, Staff Reporter
This story appears in the June 25 print edition of Transport Topics.
Freightliner LLC and Paccar units Kenworth Trucks and Peterbilt Motors all said they are offering electronically controlled air disc brakes as an option in 2007, promoting them as safer and easier to maintain than the drum brakes most U.S. heavy trucks use.
Kenworth, which introduced disc brakes at truck shows last year but offered them only for limited sales, “made them a full-fledged option this year, educating our dealers about them and putting them in all our promotional material,” spokesman Jeff Paretti said.
Kenworth announced this month it will include disc brakes in trucks it is promoting in a dealer tour; those trucks have a Bendix electronic stability control system that has anti-rollover capability and is integrated with the brakes.
Peterbilt is also offering them as a full option in 2007, spokeswoman Melissa Epping said, and a Freightliner executive outlined the advantages of air disc brakes.
“Drum brakes are excellent, but air disc brakes have an advantage over them in being able to repeatedly provide shorter stops in severe conditions, such as downhill grades or slowing down from a highway speed,” Tony Moore, Freightliner’s director of brake and chassis systems, told Transport Topics.
Brake manufacturers and others said the disc brakes now available are much better than systems introduced in the 1970s, which had numerous problems, causing fleets in the U.S. to avoid them.
“Tremendous strides have been made since the 1970s to upgrade disc brakes using the latest in electronics, computers and composite materials, to where they are far superior to drum brakes that most heavy trucks use,” Duane Perrin, president of the truck-safety consulting firm Truckpertise LLC, McLean, Va., told Transport Topics.
At present, less than 1% of over-the-road trucks in the United States and Canada are outfitted with air disc brakes, versus 75% to 90% of tractors and 70% of trailers in Europe, brake manufacturers said.
Brake producers and original equipment manufacturers listed several advantages of disc brakes, which can:
• Stop a truck in a shorter space than drum brakes.
• Avoid the brake fade that causes drum brakes to lose effectiveness in hard or repeated stopping.
• Hold a straight path in hard braking.
• Offer easier handling in both stop-and-go and highway travel.
• And are simpler and cheaper to maintain.
The faster a truck travels, the greater effect disc brakes have, manufacturers said.
The three major firms producing heavy-duty air disc brakes in the United States are: Bendix Spicer Foundation Brake LLC, a joint venture of Bendix Commercial Vehicle Systems and Dana Corp.; Meritor WABCO Braking Systems and Controls, a joint venture of ArvinMeritor Inc. and WABCO, the vehicle control systems business of American Standard Cos.; and Haldex Commercial Vehicle Systems, U.S.-based subsidiary of Haldex, a publicly traded Swedish company.
Matt Resch, product manager for Haldex Commercial Vehicle Systems, told TT that in side-by-side tests, “traveling 60 miles per hour, a truck and trailer with Haldex air disc brakes stopped between 190 and 206 feet, versus 250 to 265 feet for a truck with all drum brakes.”
“Once the drum brakes heated up to 500 degrees Fahrenheit, it took the truck 280 to 300 feet to stop, versus . . . 200 feet with heated disc brakes,” Resch said.
Ron Plantan, principal engineer for Bendix Spicer, said Bendix did tests at 75 mph, “because more than 40 states have speed limits between 65 and 76 miles per hour.”
“The stopping distances for the air-disc-brake-equipped truck was 305 to 325 feet, versus 450 to 518 feet for cold drum brakes,” Plantan said. “Heated drum brakes took more than 750 feet to halt, while hot disc brakes still stopped within approximately 320 feet.”
Paul Johnston, senior director, compression and braking for Meritor WABCO, said air disc brakes also give trucks greater stopping power because larger brakes can be attached to the front axle.
“Truckers with drum brakes want to have only a small system on the front axle, because if you hit the pedal hard, the truck can swerve wildly from side to side,” Johnston said. “Air disc brakes on front tires, because of how they work, will never make the vehicle veer and so can be much larger.”
All producers said the disc system was far easier and less expensive to maintain.
“Relining air disc brakes is very simple,” Resch of Haldex said. “The mechanic just has to remove one bolt from each caliper, drop in a new brake pad, refasten the bolt and you’re ready to go.”
Peterbilt and Kenworth offer only Bendix Spicer brakes; Freightliner offers different brands, according to application, but declined to name them.
“Right now, air disc brakes cost 25 to 35% more than upgraded drum brakes,” Johnston of Meritor WABCO said. “Our goal is to cut the price of air disc brake to the same cost of the larger drum brakes coming onto the market to meet the new federal stopping regulation.”
Volvo Trucks North America, Mack Trucks and International Truck & Engine Corp. told TT they do not offer disc brake options on their Class 8s.
This story appears in the June 25 print edition of Transport Topics.
Freightliner LLC and Paccar units Kenworth Trucks and Peterbilt Motors all said they are offering electronically controlled air disc brakes as an option in 2007, promoting them as safer and easier to maintain than the drum brakes most U.S. heavy trucks use.
Kenworth, which introduced disc brakes at truck shows last year but offered them only for limited sales, “made them a full-fledged option this year, educating our dealers about them and putting them in all our promotional material,” spokesman Jeff Paretti said.
Kenworth announced this month it will include disc brakes in trucks it is promoting in a dealer tour; those trucks have a Bendix electronic stability control system that has anti-rollover capability and is integrated with the brakes.
Peterbilt is also offering them as a full option in 2007, spokeswoman Melissa Epping said, and a Freightliner executive outlined the advantages of air disc brakes.
“Drum brakes are excellent, but air disc brakes have an advantage over them in being able to repeatedly provide shorter stops in severe conditions, such as downhill grades or slowing down from a highway speed,” Tony Moore, Freightliner’s director of brake and chassis systems, told Transport Topics.
Brake manufacturers and others said the disc brakes now available are much better than systems introduced in the 1970s, which had numerous problems, causing fleets in the U.S. to avoid them.
“Tremendous strides have been made since the 1970s to upgrade disc brakes using the latest in electronics, computers and composite materials, to where they are far superior to drum brakes that most heavy trucks use,” Duane Perrin, president of the truck-safety consulting firm Truckpertise LLC, McLean, Va., told Transport Topics.
At present, less than 1% of over-the-road trucks in the United States and Canada are outfitted with air disc brakes, versus 75% to 90% of tractors and 70% of trailers in Europe, brake manufacturers said.
Brake producers and original equipment manufacturers listed several advantages of disc brakes, which can:
• Stop a truck in a shorter space than drum brakes.
• Avoid the brake fade that causes drum brakes to lose effectiveness in hard or repeated stopping.
• Hold a straight path in hard braking.
• Offer easier handling in both stop-and-go and highway travel.
• And are simpler and cheaper to maintain.
The faster a truck travels, the greater effect disc brakes have, manufacturers said.
The three major firms producing heavy-duty air disc brakes in the United States are: Bendix Spicer Foundation Brake LLC, a joint venture of Bendix Commercial Vehicle Systems and Dana Corp.; Meritor WABCO Braking Systems and Controls, a joint venture of ArvinMeritor Inc. and WABCO, the vehicle control systems business of American Standard Cos.; and Haldex Commercial Vehicle Systems, U.S.-based subsidiary of Haldex, a publicly traded Swedish company.
Matt Resch, product manager for Haldex Commercial Vehicle Systems, told TT that in side-by-side tests, “traveling 60 miles per hour, a truck and trailer with Haldex air disc brakes stopped between 190 and 206 feet, versus 250 to 265 feet for a truck with all drum brakes.”
“Once the drum brakes heated up to 500 degrees Fahrenheit, it took the truck 280 to 300 feet to stop, versus . . . 200 feet with heated disc brakes,” Resch said.
Ron Plantan, principal engineer for Bendix Spicer, said Bendix did tests at 75 mph, “because more than 40 states have speed limits between 65 and 76 miles per hour.”
“The stopping distances for the air-disc-brake-equipped truck was 305 to 325 feet, versus 450 to 518 feet for cold drum brakes,” Plantan said. “Heated drum brakes took more than 750 feet to halt, while hot disc brakes still stopped within approximately 320 feet.”
Paul Johnston, senior director, compression and braking for Meritor WABCO, said air disc brakes also give trucks greater stopping power because larger brakes can be attached to the front axle.
“Truckers with drum brakes want to have only a small system on the front axle, because if you hit the pedal hard, the truck can swerve wildly from side to side,” Johnston said. “Air disc brakes on front tires, because of how they work, will never make the vehicle veer and so can be much larger.”
All producers said the disc system was far easier and less expensive to maintain.
“Relining air disc brakes is very simple,” Resch of Haldex said. “The mechanic just has to remove one bolt from each caliper, drop in a new brake pad, refasten the bolt and you’re ready to go.”
Peterbilt and Kenworth offer only Bendix Spicer brakes; Freightliner offers different brands, according to application, but declined to name them.
“Right now, air disc brakes cost 25 to 35% more than upgraded drum brakes,” Johnston of Meritor WABCO said. “Our goal is to cut the price of air disc brake to the same cost of the larger drum brakes coming onto the market to meet the new federal stopping regulation.”
Volvo Trucks North America, Mack Trucks and International Truck & Engine Corp. told TT they do not offer disc brake options on their Class 8s.
