Brake Safety Week: Bendix shares tips on how to prepare and what to expect
AVON, Ohio – In trucking, like in life, there’s nothing like being prepared, whether it’s the next load, the next storm, or the next inspection. And inspections are currently the number one priority in the North American commercial vehicle industry as one of the biggest touchpoints on the calendar approaches: Brake Safety Week, taking place August 21-27. The annual week-long event hosted by the Commercial Vehicle Safety Alliance (CVSA) examines vehicles in the United States, Canada and Mexico. The Bendix Commercial Vehicle Systems LLC (Bendix) team offers suggestions on how to prepare.
“During last year’s CVSA Brake Safety Week, 12% of the 35,764 vehicles inspected were taken out of service due to brake issues,” said Fred Andersky, Bendix director of demos, sales and service training. “So many aspects of safe vehicle operation are directly affected by what goes on at the wheel ends and in the braking system that it really cannot be overemphasized how important it is to keep up with maintenance and inspection of these areas. From stopping power to the performance of higher-level technologies like collision mitigation, it all depends on how well the brakes and wheel ends work when they’re needed. This is why these inspections are so important and Bendix is sharing practical tips on preparation and safety.”
Brake Safety Week is part of CVSA’s Operation Airbrake initiative, an awareness and enforcement campaign aimed at reducing the number of highway accidents caused by faulty commercial vehicle braking systems. At the event, local, state, provincial, territorial and federal auto transporter safety officers in the United States, Canada and Mexico inspect large trucks and buses with a focus on braking system violations.
What to expect:
Brake Safety Week road inspectors conduct North American standard inspections covering a range of driver qualifications, documentation and vehicle equipment conditions.
You will check for:
Missing, non-functioning, loose, contaminated, or cracked parts. Punctures caused by rust and by rubbing or rubbing. Broken springs in the parking brake spring accumulator housing part. Air leaks around brake components and lines. Air pressure in the target range of 90-100 psi. Slack adjusters not the same length. Mismatched air chamber sizes across axles. Functionality of warning devices (e.g. anti-lock braking system indicator lights).
Inspectors will also look for violations of brake hose and hose chafing, which are the focus of this year’s Brake Safety Week.
How to prepare:
“Pre, post and periodic inspections can go a long way in uncovering some obvious violations, including loose hoses or damaged components like air sleeves or pushrods,” said Mark Holley, Bendix director of marketing and customer solutions, Wheel-End. He recommends the following:
Check for damaged or loose air cans, pushrods, or slack adjusters. Make sure the slack adjusters are extended at the same angle on each axle. Different angles can indicate an incorrectly adjusted brake or a broken spring brake force spring. Examine the condition, positioning and connections of pipes and hoses.
Perform a 90 to 100 psi brake apply with the wheels chocked and the parking brakes off and check for leaks. Check the air disc brake rotors for cracks. Check drum brake pads for wear and cracks.
Check the air system for moisture to avoid contamination that leads to component degradation and system leaks.
“It also pays to lubricate the S-cam brake hoses and automatic slack adjusters every time you have a vehicle in the shop,” Holley said. “This quick process helps prevent rust and corrosion and keeps the slack working properly.”
With regard to brake hose and pipe chafing, the focus of this year’s Brake Safety Week, Bendix recommends looking out for two typical causes. The first is improper routing and cutting, which can result in hoses rubbing against each other while the vehicle is in operation. Preventive measures include regular inspections to ensure zip ties, clips and mounts are not damaged or broken. The second typical cause is an incorrect hose length, a replacement hose that is too long is prone to chafing. Damaged hoses should be replaced.
“Also, from an overall perspective, never underestimate the importance of communication between drivers and technicians,” said Andersky. “A driver on the road may be the first to notice a problem with the truck. Being able to tell the technician what happened, where and other details like weather conditions is just as important as the technician asking questions to better understand the situation.”
Andersky continued: “This is all part of the holistic approach to maintenance, which is crucial when you consider the complex interconnectedness of the entire braking system and more advanced safety technologies. Any sign that something is out of specification can point to broader maintenance issues. That means that in and of itself things like an active parking light on the dash or a kink in an air hose – and anything else that inspectors look for – matter.”
How drums and discs differ:
As for Brake Safety Week, air disc brakes and drum brakes have a few different maintenance requirements.
“The most important difference is the measurement of the brake stroke,” said Holley. “Because air disc brakes have an internal adjustment mechanism, their braking distance is not measured externally, as is the case with drum brakes. The internal adjustment mechanism significantly reduces the risk of deviations from the adjustment.”
Measuring the chamber travel of a drum brake consists of checking the distance from the air chamber to the clevis pin with the brakes released and then again after a fully loaded brake application. The difference between these is the brake stroke, and its maximum length depends on the type and size of the brake cylinder.
Improperly adjusted brakes can also drag, affecting fuel efficiency and accelerating pad wear or experiencing reduced braking performance. Bendix has developed an infographic (below and attached) to highlight the different service requirements of air disc and drum brakes.
Choose the right parts:
When you realize it’s time for new brake pads, make sure you meet the specifications: not all brake pads marketed as “acceptable” under current Reduced Stopping Distance (RSD) regulations actually meet this standard. Whether you’re replacing air disc brake pads or drum brake shoes, select components that ensure original equipment manufacturer (OEM) requirements are met to keep the vehicle compliant.
“The aftermarket is busier than ever, especially when it comes to brake friction,” said Holley. “The wrong choice can damage your system and undermine vehicle safety. Complications resulting from improper friction selection can include cracks, deterioration in braking performance, or damage to other wheel end components. Remember these are things a road inspector will notice and penalize you for.”
When it comes to remanufactured drum brake shoes, ask your supplier if they’ve been stamped back to their OEM-designed shape rather than simply lined with new friction, Holley noted. Shoes deform under the stress of regular use, and relining one of these shoes without restoring it to its original geometry can compromise braking power and friction life.
You should also protect the air supply from corrosive oil aerosols that cause leaks and potential injury. Bendix recommends using an oil coalescing air dryer cartridge such as the Bendix PuraGuard. Oil coalescing cartridges can be used as a replacement for standard cartridges, but the reverse is not true: you should not upgrade from an oil coalescing cartridge to a standard cartridge.
Technicians equipped with the latest knowledge and tools are instrumental in keeping vehicles on the road and in good operating condition. Bendix offers a variety of resources that provide the most up-to-date and comprehensive training and information including: The Bendix Document Library, Service Data Sheets, User Guides, Technical Bulletins and a variety of other documents providing detailed information including maintenance and troubleshooting. The Bendix Brake Training School, long-standing hands-on training programs, are conducted in-person in the United States, with some virtual options available.
Here is the schedule for 2022. The Bendix Online Brake School [www.brake-school.com]www.brake-school.com. You will find more than 90 courses covering the entire spectrum of product topics such as braking and active vehicle safety. Registration is free and the site serves more than 130,000 registered users. “Truck Talk with Bendix” This podcast is available on Google Play, Apple Podcasts and Stitcher.
Bendix knowledge dock [www.knowledge-dock.com]www.knowledge-dock.com. This site contains an archive of the Bendix Tech Tips series, as well as videos, white papers, and other insights.
The Bendix team of seasoned sales and service professionals along with their experienced field technical support team and the Bendix Tech team at 1-800-AIR-BRAKE also provide expert technical support such as service advice, braking system troubleshooting and product training.
About Bendix Commercial Vehicle Systems LLC:
Bendix Commercial Vehicle Systems, a member of Knorr-Bremse, develops and supplies leading active safety technologies, energy management solutions, and air brake charging and control systems and components for medium and heavy-duty trucks, tractors, trailers, buses and other commercial vehicles under the Bendix brand name throughout North America . As an industry pioneer with more than 4,400 employees, Bendix and its wholly owned subsidiary RH Sheppard Co., Inc. strive to deliver the best solutions for improved vehicle safety, performance and total cost of ownership. Contact us at 1-800-AIR-BRAKE (1-800-247-2725) or visit us bendix.com.