Brake Safety Week is coming up soon, and the entire North American commercial vehicle industry knows it—so there’s no reason not to be ready. Still, last year’s Commercial Vehicle Safety Alliance (CVSA) weeklong inspection event saw nearly 5,200 vehicles across the United States, Canada, and Mexico removed from service for brake-related violations.
“So many of these out-of-service violations—situations that present actual hazards to roadway safety for the drivers and everyone around them—are preventable through proper maintenance practices and regular equipment examination,” said Fred Andersky, Bendix director of demos, sales, and service training. “With Brake Safety Week 2021 set for August 22-28, now is the time for fleets and owner-operators to prepare, not just with the goal of passing inspections, but to help make sure that vehicles are running at their safest, and that today’s higher-level safety systems like full stability and collision mitigation are supported by optimally maintained brakes at the wheel-ends.”
Brake Safety Week is part of CVSA’s Operation Airbrake initiative—an outreach and enforcement campaign that aims to reduce the number of highway crashes caused by faulty brake systems on commercial motor vehicles. The event involves local, state, provincial, territorial, and federal motor carrier safety officials in the United States, Canada, and Mexico inspecting large trucks and buses, focusing on brake system violations.
What to expect during inspection
Brake Safety Week roadside inspectors regularly conduct North American Standard Inspections, which cover a range of driver qualifications, documentation, and vehicle equipment conditions. Where brake systems, in particular, are concerned, they’ll be checking for:
- Loose or missing parts
- Air or hydraulic fluid leaks
- Trouble-indicator lights on the dash, including antilock brakes (ABS)
- Worn linings, pads, drums, or rotors
- Mismatched air chamber sizes across axles
- Warning device functionality (such as antilock braking system indicator lights)
- Proper brake adjustment
- Brake hoses and tubing condition (a special focus for this year)
When possible, inspectors will measure pushrod stroke to ensure brakes are properly adjusted. Drivers can incur fines if more than 25% of a vehicle’s wheel-ends are out of adjustment, and too many out-of-adjustment brakes can lead to the vehicle being placed out of service.
How to get ready and prevent violations
What you do in the shop and during pre-trip walkarounds—looking at every aspect of your vehicle—can make an important difference on the road and during a brake system inspection, simply by catching brake-related issues before they become problems.
Every day:
- Check for damaged or loose-hanging air chambers, pushrods, or slack adjusters.
- Make sure slack adjusters on each axle are extended out to the same angle. Different angles can indicate an out-of-adjustment brake or a broken spring brake power spring.
- Examine tubing and hose condition, positioning, and connections.
Every week:
- Perform a 90- to 100-psi brake application with the wheels chocked and the parking brakes released, and listen for leaks.
- Check air disc brake rotors for cracks.
- Inspect drum brake linings for wear and cracks.
Every month:
- Check for moisture in the air system to prevent contamination that leads to component deterioration and system leaks.
“Any time you’ve got a vehicle in the shop, it’s also worth greasing the S-cam brake tubes and automatic slack adjusters: This quick process helps prevent rust and corrosion and helps keep the slack functioning properly,” said Mark Holley, Bendix director of marketing and customer solutions—Wheel-End. “Additionally, Bendix recommends that before drivers get on the road, they routinely perform 90- to 100-psi brake applications – with the wheels chocked and the parking brakes released – and listen for leaks that might be attributed to hoses and/or tubing.”
Drum and disc differences
Air disc brakes and drum brakes have a few differing maintenance needs where Brake Safety Week is concerned, key among them the measurement of brake stroke. Because air disc brakes include an internal adjustment mechanism, their brake stroke is not measured externally, as is the case with drum brakes.
“Measuring a drum brake’s chamber stroke is a matter of checking the distance from the air chamber to the clevis pin with the brakes released, and then again after a fully charged brake application,” Holley explained. “The difference between these is the brake stroke, and its maximum length depends upon the brake chamber type and size.”
Improperly adjusted brakes can also drag—impacting fuel efficiency and speeding up pad wear—or experience decreased stopping power. Bendix has developed an infographic (included below and attached) to note the differing maintenance needs of air disc and drum brakes.
Parts selection and brake system health
When it’s time to replace a component in your brake system, whether it’s at the wheel-end or in the air supply, be sure to select parts that won’t degrade the performance level or bring it below the original equipment manufacturer’s standards.
“This is particularly true when it comes to brake friction, where the aftermarket is more crowded than ever, and the wrong choice can actually harm your system and your vehicle safety,” Holley said. “Not all replacement linings that are marketed as acceptable for federal stopping distance requirements will actually perform to the standard. Other complications arising from improper friction selection can include cracks, degradation of braking performance, or damage to other wheel-end components. And again, these are things that a roadside inspector will note and penalize you for.”
To protect the air supply against corrosive oil aerosols that lead to leaks and potential violations, Bendix recommends using an oil-coalescing air dryer cartridge. It’s important to note that while oil-coalescing cartridges can be used to replace standard cartridges, the reverse is not the case: You shouldn’t downgrade from an oil-coalescing cartridge to a standard.
Parts and the whole
“Taken individually, these things that inspectors are looking for—an active full-stability light on the dash, a kink in an air hose—may seem inconsequential,” Andersky said. “But the complex interconnectivity of the entire brake system and more advanced safety technologies mean it’s critical to take this holistic approach to upkeep. One small sign of something out of compliance can be an indicator of more widespread maintenance issues.”
