Pre-Trip Inspection Flashcards

When inspecting the air brake system during a pre-trip, what should you check regarding the air compressor?

Answer: All of the above.

During a pre-trip inspection, it's crucial to thoroughly check the air compressor. This includes verifying that it is securely mounted, free from any visible damage or leaks, and operating correctly. You must confirm that it builds and maintains air pressure within the specified range by turning on and off automatically, ensuring the entire air brake system is functional.

How do you check for leaks in the air brake system?

Answer: Apply full brake pressure, turn off the engine, release the brakes, and watch the pressure gauge.

To properly check for leaks in the air brake system, you should build up full air pressure, then turn off the engine. With the engine off, apply the service brakes fully for one minute and observe the air pressure gauge. A drop of more than 3 psi for single vehicles or 4 psi for combination vehicles indicates a leak that needs to be addressed.

What is the proper way to test the low air pressure warning system?

Answer: Press the brake pedal repeatedly until the warning light or buzzer activates.

To test the low air pressure warning system, you should turn off the engine (with the key on) and repeatedly press the brake pedal. This action gradually releases air from the tanks. The warning light and/or buzzer should activate before the air pressure drops below 60 psi, indicating that the system is functioning correctly to alert the driver of critically low air pressure.

How do you test the parking brake during a pre-trip inspection?

Answer: By applying the parking brake and gently pulling against it in a low gear.

To test the parking brake during a pre-trip inspection, you should engage the parking brake, put the vehicle in a low gear (like first gear or drive), and gently attempt to pull forward. The vehicle should resist movement, indicating that the parking brake is holding effectively. This confirms the parking brake's ability to secure the vehicle.

How do you perform the air pressure build-up test?

Answer: Ensure the compressor builds pressure from 85 to 100 psi within 45 seconds.

The air pressure build-up test verifies the efficiency of the air compressor. With the engine at operating RPM, the compressor should be able to build air pressure from 85 psi to 100 psi within 45 seconds. This test ensures the compressor can quickly replenish air pressure, which is vital for safe and effective braking.