CDL General Knowledge TestCombination Vehicles (if applicable)Medium
A driver is performing a pre-trip inspection of the air brake system on a combination vehicle. After building full air pressure, the governor cut-out pressure should be between:
- A100 and 125 psi.
- B125 and 150 psi.
- C150 and 175 psi.
- D80 and 100 psi.
Show answer & explanationAnswer & explanation
Correct answer: A. 100 and 125 psi.
The air compressor governor cuts out (stops compressing air) when the system reaches its maximum operating pressure, which is typically between 100-125 psi. This ensures the system doesn't over-pressurize.
Why the other options are wrong
- B. This range is too high for the governor cut-out.
- C. This range is significantly too high for the governor cut-out.
- D. This range is too low for the governor cut-out.
Air Compressor Governor Cut-Out Pressure
The pressure range at which the air compressor stops pumping air into the system, typically between 100-125 psi, to prevent over-pressurization.
- Regulates maximum system air pressure.
- Protects system components from damage.
- Must be checked during pre-trip inspection.
Memory trick: One hundred to one twenty-five, keeps your air system alive.