Putting the Brakes on Air Brake Failure

There’s a hidden danger on the highways. Most drivers probably aren’t even aware of it, because it’s not as obvious as traffic snarls or distracted driving. The culprit is defective brakes on air brake equipped commercial vehicles.

Air brake deficiencies are a factor in more than 25% of all serious truck crashes resulting in fatalities or injuries, according to a 2006 study by the U.S. Department of Transportation. This represents a much more serious risk than other obvious risk factors, such as traffic flow interruption, prescription drug use, unfamiliarity with roadways and driver distraction.

This should be a serious concern for insurers, their commercial trucking clients and the brokers that represent them. Air brake problems can lead to poor safety records, an increased number of claims and higher insurance premiums. They are literally a matter of life and death out on the road.

An ounce of prevention – in the form of basic maintenance and education – can go a long way in minimizing air brake malfunctions.

MAINTENANCE OVERLOOKED

Air brakes are typically used on buses, trucks, tractors and other heavy-duty vehicles; they require constant inspection and attention to ensure proper operation and performance. However, statistics show that air brake maintenance and adjustment is often overlooked.

Brake malfunction accounted for 56.6% of out-of-service violations cited during roadside inspections. This was followed by lights (11.1%), loading (9.3%) and tires/wheels (8.5%), according to a 2004 study by the Commercial Vehicle Safety Alliance (CVSA), a Washington, D.C.-based association of state, provincial and federal officials that administers and enforces motor carrier safety laws in Canada, Mexico and the United States.

It’s not surprising, then, that air brake deficiency is cited as one of the major factors in truck crashes, according to the 2006 Large Truck Crash Causation Study, conducted by the U.S. Department of Transportation’s (DOT) Federal Motor Carrier Safety Administration and the National Highway Traffic Safety Administration (NHTSA).

In the category of “all trucks involved in crashes nationwide by specific factors,” the study shows that brake deficiency was cited in 37,000 (or 26% of) vehicle crashes. This compares with crashes resulting from prescription drug use (26%), travelling too fast for conditions (23%), weather-related factors (14%), fatigue (13%), aggressive driving (7%), jackknife events (5%), cargo shift (4%) or engine, fuel system or exhaust deficiency (1%). It should be noted that multiple causes could be cited for a single crash.

It’s unclear whether these crashes could have been prevented with proper air brake maintenance, but maintenance is only part of the picture. Industry surveys repeatedly determine that truck drivers and mechanics need more education and awareness of how air braking systems operate and how to inspect and maintain them.

EDUCATION IS KEY

Education about air brake systems is the key to eliminating crashes caused by brake defects, safety violations and costly roadside brake repairs, according to Collin Mooney, the director of enforcement programs for CVSA. Such education would be directed at drivers, inspectors and mechanics.

Zurich, for example, recognized a need for training and education in an easily accessible and interactive format. This led to the development of Virtual Risk Manager – Airbrakes, a web-based training program designed to help improve commercial motor safety across North America. Zurich has formed a “strategic alliance” with CVSA to raise awareness and promote airbrake education in the transportation industry through the availability of this new online program.

The program features instructional animations and a narrator. Starting with a brief knowledge assessment, the program uses simple point-and-click navigation to walk users through a series of up to 15 training modules designed to help them master the concepts and practicalities of air brake technology. You can see a free demonstration of the program at www.virtualriskmanager.net/airbrakes.

Air brakes are an indispensable part of conducting business in today’s trucking industry. Don’t let your customers take chances; stress the importance of maintenance and education in keeping their fleets safe out on the road.

Air Brakes: Test Your Knowledge

Test your air-brake knowledge with these questions from the Virtual Risk Manager course:

Questions:

1. What is the minimum operating pressure for vehicle air brake systems?

2. A vehicle’s air pressure build-up rate is too low when ______?

3. What is the correct cut-in and cut-out governor pressure for the air compressor?

4. Under what circumstances should a driver manually adjust brakes equipped with self-adjusting brake adjusters (SABAs)?

Answers:

1. No less than 85 psi for a bus and no less than 100 psi for a truck.

2. It takes longer than two minutes for air pressure to rise from 85 psi to 100 psi at 600 to 900 rpm.

3. Cut-out pressure is between 120 and 135 psi. Cut-in pressure is 20 to 25 psi below cut-out pressure.

4. A driver should never manually adjust brakes equipped with SABAs; failure to maintain adjustment automatically indicates a defect that must be repaired.