The expert offers tips on navigating Brake Safety Week, which begins on Sunday
AVON, Ohio — In trucking, like in life, there’s no substitute for being prepared — whether it’s the next load, the storm, or the 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 event of Commercial Vehicle Safety Alliance (CMVSA) examines commercial vehicles in the United States, Canada and Mexico.
To help the drivers prepare, the team lends a hand Bendix Commercial Vehicle Systems LLC offers some suggestions.
“During the last year 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 freeway accidents caused by faulty commercial vehicle braking systems. At the event, local, state, provincial, territory 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 pipe chafing – the focus of this year’s Brake Safety Week.
How to get ready
“Priority, secondary and regular 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 at 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.”
When it comes to brake hose and hose chafing, Bendix recommends looking for two common 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 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. It’s important to be able to tell the technician what happened, where and other details like the weather conditions – as well as the technician asking questions to better understand the situation.”
Andersky said it’s all part of the holistic approach to maintenance, which is critical given the complex interconnectedness of the entire braking system and more advanced safety technologies.
“Any sign that something is out of compliance can point to broader maintenance issues,” Andersky said. “That means, individually, things like an active parking light on the dashboard or a kink in an air hose – and everything 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 experience 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
If you decide it’s time for new brake pads, make sure you’re meeting 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,” Holley said. “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 the use of oil coalescing air dryer cartridges, which can be used as a replacement for standard cartridges.
However, the reverse is not true: one should not switch from an oil coalescer cartridge to a standard cartridge.
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