CVSA statistics reveal “60% of Out-of-Service Brake defects could have been discovered with a good pre-trip inspection”. If the technician is able to apply and observe the brake operation with controlled air pressure at the axle on both the trailer and truck, these numbers will drop.
Brakes comprised the largest percentage of 52 percent, of Out-of-Service Violations (OOSV) cited in roadside inspections conducted during Road check 2011 and the percentages have not significantly changed for the past 3 years.
This suggests non-uniform or non-existent brake inspection procedures especially on the out-bound lane.
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 creating an unreliable process. The requirements for quality brake inspections are straight forward. Additional information is outlined in the TECHNICAL MAINTENANCE COUNCIL’s (TMC) Recommended Practices.
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 may 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 (fittings, air line damage, hub seals, air bags, etc.)
- Identify internal air loss (valve seals, chamber leakage, etc.)
Observe the brake mechanical operation at the wheels with a remote allowing one technician to control the process with regulated air pressures.
- Slack adjustments will be correct and consistent.
- Reduce automatic slack 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.
The LITE-CHECK Inspectors vehicle tester performs the above procedures following TMC’s Recommended Practices. With the full remote control operation, a complete trailer inspection should require only 5 minutes by one technician including slack adjustments. The LITE-CHECK Pedal Actuator performs the service brake operation on a truck at the axle inspection.
Bob Blair, CEO