Brake Safety Week is Aug. 25-31 and Bendix Commercial Vehicle Systems offers these tips for making sure vehicles are up for the challenge.
"During last year's CVSA Brake Safety Week, nearly 13% of the 18,875 vehicles inspected — a total of 2,375 — were placed out of service for brake-related issues," says TJ Thomas, Bendix's director of marketing and customer solutions for controls. "So many violations are preventable through proper maintenance practices and regular equipment examination. You simply can't overstate the importance of keeping up with maintenance and examination of the wheel-ends and braking system, because so many aspects of safe vehicle operation are directly impacted by what goes on in those areas."
Brake Safety Week is run by the Commercial Vehicle Safety Alliance throughout the United States, Canada and Mexico. It's part of Operation Airbrake, an outreach and enforcement campaign that hopes to reduce the number of crashes caused by faulty brake systems on commercial motor vehicles.
What to expect
Brake Safety Week roadside inspectors will conduct North American Standard Inspections. These cover driver qualifications, documentation and vehicle equipment conditions. Inspectors will look for:
- Missing, nonfunctioning, loose or cracked parts.
- S-cam flip-over.
- Air leaks around brake components and lines.
- Slack adjusters not at the same length.
- Mismatched air chamber sizes across axles.
- Air pressure in the target range of 90-100 psi.
- Holes caused by rust and through rubbing and friction.
- Broken springs in the spring brake housing section of the parking brake.
- Proper pushrod travel.
- Warning device functionality.
- Proper operation of the tractor protection system, including the bleed-back system on the trailer.
- The breakway system being operable on the trailer.
This year, Bendix says inspectors will focus on contaminated, worn, cracked and missing linings or pads.
Some of the things inspectors are looking for seem inconsequential, Thomas says, but it's important to remember that all of the vehicle's systems are connected.
"Any indication of something out of compliance can be a sign of potentially wider maintenance issues," he says. "It's critical to take a holistic approach to upkeep when considering the complex interconnectivity of the entire brake system and more advanced safety technologies. One small sign of something out of compliance can be an indicator of more widespread maintenance issues."
How to prepare
Brian Screeton, manager of technical training and service and Bendix, says regular inspections can help catch brake issues before they become a problem. He recommends the following schedule of inspection:
Daily
- 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.
Weekly
- 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.
Monthly
- 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," Screeton says. "This quick process helps prevent rust and corrosion and it helps keep the slack functioning properly."
Drums versus discs
Air disc brakes and drum brakes have different maintenance needs.
"Key among the differences is the measurement of brake stroke," Screeton says. "Because air disc brakes include an internal adjustment mechanism, their brake stroke is not measured externally as is the case with drum brakes. The internal adjustment mechanism significantly lowers the risk of out-of-adjustment violations."
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. The difference is the brake stroke. Its maximum length depends upon the brake chamber type and size.
Improperly adjusted brakes can also drag, which impacts fuel efficiency and speeds up pad wear, or have decreased stopping power.
Select the correct parts
If it's time for new brake friction, Bendix says to make sure to keep things up to spec. Not all friction that is marketed as acceptable under current reduced stopping distance (RSD) regulations will actually perform to that standard.
"The aftermarket is more crowded than ever, particularly when it comes to brake friction," Thomas says. "The wrong choice can harm your system and undermine vehicle safety. Complications arising from improper friction selection can include cracks, degradation of braking performance or damage to other wheel-end components. Remember, these are things that a roadside inspector will note and penalize you for."
Bendix recommends using an oil-coalescing air dryer cartridge to protect the air supply from corrosive oil aerosols that lead to leaks and potential violations. Oil-coalescing cartridges can be used to replace standard cartridges, but the reverse is not the case. Don't downgrade from a oil-coalescing cartridge to a standard, Bendix warns.
Tech support
It's important for drivers and technicians to communicate about the condition of a vehicle, Bendix experts say.
"A driver on the road may first notice an issue with the truck," Thomas says. "It's critical that the driver be able to tell the technician what happened, where it happened and details such as weather conditions. And it's just as vital for the technician to ask questions to gain a clearer understanding of the situation."
Technicians should also remain current on commercial vehicle safety components and technologies. Bendix offers several options for staying informed, including:
- Brake Training School in-person and hands-on sessions across the country.
- A free On-Line Brake School with more than 100 maintenance courses and tests for sharpening technical skills.
- The Truck Talk with Bendix podcast is available on Google Play, Apple Podcasts, Stitcher and on the Bendix Knowledge Dock.
- The Bendix Document Library has service data sheets, operating manuals, technical bulletins and other information.
