New Meritor discs specifically for linehaul

ATLANTA, Ga. – Meritor is moving forward with a system designed for better stops – the new Meritor EX+ LS air disc brakes that are purpose-built for linehaul and trailer applications.

“What we tend to do as an industry is develop a brake that is built for refuse, all the way down to medium-duty. It’s a one-size-fits all. So we took more of an optimized approach and that allowed us to take some weight out of the product,” said TJ Reed, vice-president – front drivetrain.

Weighing in at 71 lb., it’s promoted as the lightest air disc brake available.

“Our EX+ L that’s currently in the market weighs in at about 74.5 lb. and that is the lightest truck brake in the market today,” he said in an interview with

The savings have come through the castings and single-piston design.

But it’s about more than shedding pounds. The company says the design is built to last, and has accumulated more than 1.5 million km of field testing while running through the paces of 330 internal lab tests. It’s taken more than four years to bring it to market.

The 86-mm piston diameter is twice as wide as competing models, which Reed says will minimize taper wear and maximize pad life. Adjuster mechanisms have been sealed from the elements, too.

“The challenge with a single-piston brake has always been taper wear – uneven wear on the pads. The way we’re able to mitigate that is an integrated spreader plate with that large piston, so it really evenly distributes the load much better, makes for an even pad wear.”

For those looking to optimize the design, optional features include pad and rotor shields, positive pad retraction that optimizes the running clearance between the pad and rotor to extend pad life, and embedded sensors that can be used as an electronic inspection tool.

There will likely be more application-specific brake designs to come thanks to modern design tools, Reed said.

“Three of four OEMs have gone standard with air disc brakes in North America, starting last year, and fleets the last few years are adopting at a much heavier rate. Many are taking 50-100 and doing a lot of field testing.”

It’s seen as next logical spec’ to follow collision mitigation systems and advanced driver assistance systems (ADAS), he added.

Low-copper offerings

It isn’t Meritor’s only brake-related news to emerge during the North American Commercial Vehicle Show.

The supplier’s MA 9300 proprietary friction material has been approved as an N-Type offering, and meets the 2025 limits for reduced copper, skipping over the interim limits set in 2021.

“It was the right thing to do. It was a better product, it’s better for the environment,” he said of the decision to go straight to the tighter limits. “The performance of the product is better than what we have today. We’ve seen that in testing.”

“We see similar rotor wear but actually better pad wear.”

It will be interchangeable with current friction and be available by mid 2020, likely for trailers at first, Reed says.

John G. Smith is the editorial director of Newcom Media's trucking and supply chain publications -- including Today's Trucking,, TruckTech, Transport Routier, Inside Logistics, Solid Waste & Recycling, and Road Today. The award-winning journalist has covered the trucking industry since 1995.

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