BRAKES comprised the largest percentage, about 51.6%, of out-of-service violations (OOSV) cited in roadside inspections conducted during the Commercial Vehicle Safety Alliance's Roadcheck 2009.
CVSA statistics reveal “60% of out-of-service brake defects could have been discovered with a good pre-trip inspection.” This suggests non-uniform or non-existent brake inspection procedures.
Additionally, results from the Department of Transportations's most recent Large Truck Causation study indicated that brakes were a factor in 29.4% of all the crashes investigated. Better maintenance is critical.
It all starts with regular brake inspections that are performed properly. A consistent quality trailer brake inspection is possible with the right process and equipment. Too often, the air pressures are not known and the inspection may require two technicians.
The requirements for quality brake inspections are straightforward:
-
Regulated air pressures for the trailer matching the truck operation for consistent applications.
-
Excessive pressures will stress the air system, creating air leaks and mechanical damage.
-
Low pressures do not exercise the brake operation as in real life and will not show air loss.
-
Apply emergency (supply) air before the service (control) air to prevent service brake compounding creating mechanical issues.
-
Be able to perform the air test on the supply air only, and then the supply/control together.
-
Identify external air loss (including fittings, air line damage, hub seals, and air bags).
-
Identify internal air loss (such as valve seals and chamber leakage).
-
Observe the brake mechanical operation at the wheels with a remote, allowing one technician to control the process with regulated air pressures.
-
Slack adjustments must be correct and consistent.
-
Reduce automatic slack adjuster damage by releasing pressure during adjustment.
-
Verify all brake movements are in unison.
-
Observe brake movement during an air leak test.
Applying these basic principles will not only reduce road issues, but also cut maintenance costs, brake wear, and tire wear. With a full remote control operation, a trailer brake inspection should require only five minutes by one technician including slack adjustments.
With additional air-operated devices such as air bags, tire inflation systems, and automatic lube systems connected to the air systems, a consistent process is even more important.