Air Brake Test Checklist Template

The 7-step air brake test is a more comprehensive method typically used in a fleet, or CDL schools training but not usually common on CDL skills test. Before beginning the 7 essential steps below, make sure you have conducted a thorough visual inspection of the vehicle to make sure there are no other issues.

1. Test for Air-Compressor Build-Up – The first step is to check if the air-compressor cuts out when it reaches its maximum level or cut-out pressure (120-135 psi). You start by starting the engine of the vehicle and just let it idle until it builds up the pressure. If it stops pumping air, then the air-compressor works.
2. Test for Air Governor Cut-In – The next step is to fan the brakes and hold it until the air pressure drops below cut-in (around 80 psi).
3. Test for Air Leakage – The same as the first step in the 3-step procedure, this is done by turning off the engine, then switching it on again. Release the park brake, hold it, and watch the pressure drop, making sure it does not exceed 4 psi for combination vehicles (Class A) or 3 psi for (Class B) single vehicles.
4. Applied Brake Test – This is done by releasing the spring brakes, building the pressure, then shutting off the engine. Hold the brake pedal, observe the air-pressure readings, and notice the drop to confirm if there’s any problem in the system.
5. Test the Low Air Pressure Alarms – With the engine turned on, pump the brake pedal to drop the air pressure. If the low air warning light or buzzer activates, then it’s working.
6. Test the Protection Valve or Emergency Spring Brake – Ensure the protection valves are pushed in or open, then continually pump the brake to reduce air pressure until the protection valves pop out.
7. Tug Test – This final step is ensuring the parking brake and service brakes are working. Test the service brakes are working by moving the vehicle slowly at 5mph, when the service brake is applied it should stop smoothly.

Finally, whichever procedure you follow or remember during CDL tests, the most important reminder is to never operate the vehicle if there’s any issue with the air brake system. There are ways to ensure your team remembers each step, such as conducting inspections regularly to perform it naturally. Some may use a “cheat sheet” to easily remember the steps. If there’s an issue, perform a thorough inspection using an Air Brake Test Checklist to conveniently go over the check items and figure out the root cause.