Every year, during Brake Safety Week, thousands of commercial vehicles are inspected on U.S. highways to ensure that their brake systems are working properly.
In a typical year about 12% of the trucks inspected during the period, which typically occurs during the last part of August, fail and are removed from service until they are brought into compliance.
The results of the 2024 inspections have not yet been released, but during the event in 2023, 12.6% of the 18,875 trucks inspected were taken out of service due to brake-related out-of-service violations, according to the Commercial Vehicle Safety Alliance (CVSA).
The statistics show just how many trucks are on the roads with potentially faulty brake systems, which may reduce braking capacity and put drivers and others at risk.
If an accident occurs and you’ve missed an issue, your firm could be held liable if sued. Stay on top of your trucks’ brakes by adopting these tips from truckers who passed inspections during Brake Safety Week 2024.
Conduct regular inspections
A truck’s brakes should be inspected every time it is in the shop to ensure that it can safely operate on the road.
Generally, though, you should visually inspect your trucks’ air brake systems at least every three months, along with the regular and more detailed inspections as per the truck maker’s recommendations. During this process look for signs that parts are worn or damaged.
Also, vehicles that operate in harsh conditions and environments will require more frequent inspections as abrasive materials on job sites can increase wear and tear as well as corrosion.
It’s recommended that you begin the inspection at the front of the vehicle, starting with the compressor under the hood.
The compressor
Inspect the compressor drive belt for cracking and wear and check that the tension is at the correct level.
To check the compressor’s air pressure, start the engine and warm it up, after which you should run it at full-governed rpm. At that speed the pressure in the system should take 40 seconds or less to go from 85 psi to 100. If it takes longer, you’ll need to probe further for leaks in the system or problems with the compressor.
Finally check the compressor’s rings for damage or wear as they can introduce oil into the brake system if not functioning properly.
Check for leaks
The next step is to check the air system for leaks:
Static air leakage: Turn off the engine with a fully charged air system. Then, release the parking brake and time the air pressure drop. After the initial air loss, the loss rate should not be greater than 2 psi in one minute.
Service brake air leakage: With the engine off, apply the service brake firmly to 90 pounds and hold it steady. After the initial drop, the pressure should drop no more than 3 psi in one minute.
If the pressure on the gauge drops more than the above recommendations, you likely have an air leak that you’ll need to root out. One of the easiest and most reliable ways to do this is to paint the air lines and connections with soapy water and watch for bubbles.
The alternative is to use an ultrasonic leak detector, which may be faster. All leaks should be repaired.
While you’re at it, check the hoses and tubing for any cracks or wear.
Brake linings and pads
Your last defense when braking is the brake linings and pads. The only way to make sure that they are not a safety hazard is through regular inspection and thorough record-keeping that keeps track of wear.
To ensure they are fit for service and safe, the CVSA recommends that you:
- Inspect visible portions of the brake lining and pads as part of your pre- and post-trip inspections.
- Look for signs of missing lining, such as grooves in the drum from rivet contact.
- Look at the shoe-to-drum clearance and ensure there is adequate lining on the shoe.
- Look for any signs of leaks from the hub or other components that may be contaminating the lining/pad surface.
- Ensure there are no missing lining blocks/pads.
- Check for visible cracks or voids in the lining block.
- Check for any exposed rivets or lining blocks that look loose on the shoe.
- On disc brakes, pay particular attention to the condition of the rotor, such as heavily rusted rotors across the entire friction surface on either side or metal-to-metal contact.
- Make sure all repairs are consistent with the brake manufacturer’s requirements and guidelines.
- Ensure that each axle has the same linings and drums (note that it’s not required that the front axles are the same as the rear-driving ones).
Repair any issues you find or replace parts as needed. As well, once linings or pads are at the manufacturer’s recommended limit, they should be replaced.
The takeaway
Besides all of the above recommendations, you should regularly run 90- to 100-psi brake tests, listening for leaks emanating from hoses and tubes.
Always bear in mind that there are four reasons your vehicles must have properly functioning brakes:
- Public safety
- Driver safety
- Fines and penalties
- Lawsuits.