More than one-fourth of the vehicles placed out-of-service for vehicle violations during the Commercial Vehicle Safety Alliance (CVSA) International Roadcheck 2015 were flagged for brake system violations. That, says Kevin Pfost, coordinator of technical services for Bendix Spicer Foundation Brake (www.foundationbrakes.com), is the largest single share of the out-of-service vehicle violation categories, and it represents penalties that can have a direct impact on CSA scoring.
A joint venture between Bendix Commercial Vehicle Systems and Dana Commercial Vehicle Products, Bendix Spicer is an industry leader in medium and heavy truck braking and wheel-end technology. Roadcheck is the 72-hour period when approximately 10,000 CVSA-certified local, state, provincial and federal inspectors in every jurisdiction across North America perform the truck and bus inspections.
While proper preventive maintenance in the form of thorough, regularly scheduled vehicle review is crucial, Pfost says there are also several simple steps that drivers and technicians can take to keep air brake systems operating safely, and keep vehicles on the road and CSA-compliant.
DETERIORATION
Bendix’s Pfost notes that one cause of air system leaks is deterioration of components such as air seals, brake modulating valves and brake chamber diaphragms. All of these components are susceptible to premature damage if the system is contaminated by moisture – and, in particular, oil.
At least once a month, he says to check for moisture in the air brake system by opening the drain valves on the reservoirs. “Because keeping the system dry is so important, we recommend the use of OE and oil-coalescing dryer cartridges to best ensure the use of reputably-sourced and effective air dryer technology.”
ROAD PERFORMANCE
Drivers should be instructed to make note of brake system performance and any unexpected variations or decline in effectiveness while on the road, says Pfost. For instance, slow air pressure buildup in the reservoirs, rapid cycling of the air dryer or loss of pressure during the purge cycle.
They also should be mindful of rapid air loss when applying brakes or releasing the parking brake, and heed low pressure warning devices, he adds. “Brakes performing poorly upon application or exhibiting signs of dragging could be out of adjustment, or be in need of friction replacement – both of which can also be out-of-service CSA infractions.”
Also essential, stresses Pfost, is quick and effective communication between drivers and technicians. “Drivers should know what to look for and the best means of sharing questions or performance issues with their maintenance teams. Service managers need to have plans in place for addressing problems as efficiently as possible.”
