TORONTO, Ont. – The National Highway Traffic Safety Administration (NHTSA) has issued a Notice of Proposed Rulemaking that would require heavy-duty trucks to reduce their stopping distances by 20-30%.
Just how you get there is largely up to you.
There are three options which fleets and owner/operators will be able to consider once the proposal becomes law (possibly as early as 2008): all disc brakes; larger drum brakes; and a combination of disc and drum brakes. Each of the solutions would require increased brake torque on the steer axle – whether it be through the use of air disc or larger drum brakes.
“We have both disc brakes and drum brakes that will meet the stopping distances,” says Ron Plantan, principle engineer with the wheel end group of Bendix Spicer Foundation Brake. “We have a variety of options for customers, some of which have been in use for quite a few years.”
Larger drum brakes for the steer axle are already being used in the field and Plantan expects that will be a popular solution for fleets.
However, Chitta Bera, OEM Canadian sales manager with Haldex, urges fleets to give disc brakes serious consideration. While many fleets and owner/operators have been reluctant to embrace air disc brakes because of their higher cost and previous bad experiences, brake manufacturers insist today’s generation of disc brake is vastly improved. Bera also insists investing in disc brakes will pay off in the long run due to longer brake life and longer service intervals.
In Europe, 70% of new trucks roll off the assembly line with disc brakes, Bera said, adding “in Europe they’re more concerned about safety than counting pennies.”
He adds disc brakes eliminate many components, simplifying the braking system and providing for a safer operation while reducing maintenance. Bera is confident disc brakes will win out once fleets have the opportunity to test all available options.
“When the law comes in, (disc and drum brakes) will be mixed and matched for at least five years and then gradually everything will change to a disc brake system,” Bera predicts.
Bendix’s Plantan says while there were compatibility issues between disc and drum brakes in the past, those have been addressed with the current generation of disc brake products.
“We’ve done a lot of homework on compatibility,” he said, adding a disc brake-equipped tractor will work perfectly fine when pulling a drum brake-equipped trailer.
Whether or not the new ruling ends up being the catalyst that sparks the widespread adoption of disc brakes remains to be seen, but Bera is optimistic. He likens the switch to the changeover to ABS braking.
“With ABS, at the beginning everybody was complaining about it but nobody’s complaining now,” he points out.
Still, yet another price increase on new vehicles may be hard to swallow, especially considering the rule could impact other components as well.
Paul Johnston, senior director, North American Foundation Brake Business with ArvinMeritor, says changes to the suspension and ABS may be required as a result of the shorter stopping distances. He also warns of compatibility issues between the tractor and trailer.
“We must keep an eye on the resulting compatibility with existing fleet equipment,” he says.
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