CDL Air Brakes TestInspecting Air Brake SystemsEasy
During a pre-trip inspection, a driver checks the air pressure gauge. After starting the engine, the air pressure should build from 85 psi to 100 psi within what maximum time frame for a dual air system?
- A60 seconds
- B20 seconds
- C90 seconds
- D45 seconds
Show answer & explanationAnswer & explanation
Correct answer: D. 45 seconds
Federal regulations require that the air pressure in a dual air system builds from 85 psi to 100 psi within 45 seconds after starting the engine. This ensures the compressor and system are functioning correctly.
Why the other options are wrong
- A. This is too slow, indicating a potential issue with the air compressor or a significant leak.
- B. This is too fast; indicates a possible gauge malfunction or an incomplete test.
- C. This is significantly too slow and would result in failing the pre-trip inspection.
Air Pressure Build-Up Time
The maximum time allowed for the air compressor to build air pressure from a specified lower limit to a specified upper limit, indicating proper system function.
- Dual air system: 85 psi to 100 psi in 45 seconds.
- Single air system: 50 psi to 90 psi in 3 minutes.
- Ensures compressor and system integrity.
Memory trick: Fast Air Builds Quickly, Safety Prevails.