CDL Air Brakes TestAir Brake System PartsEasy
A driver is conducting a pre-trip inspection of a commercial vehicle's air brake system. They notice that the air compressor is engaged and building pressure, but the supply pressure gauges are not showing any increase in air pressure. Which component is most likely malfunctioning?
- AThe supply pressure gauges
- BThe air storage tanks
- CThe air compressor
- DThe alcohol evaporator
Show answer & explanationAnswer & explanation
Correct answer: A. The supply pressure gauges
If the air compressor is working and building pressure, but the gauges show no increase, it indicates a problem with the gauges themselves, not the air production or storage components. The gauges are responsible for displaying the pressure.
Why the other options are wrong
- B. Air storage tanks hold the air; if they were faulty, pressure would still build initially or leak, but the gauges would reflect this.
- C. The air compressor is stated to be engaged and building pressure, so it's likely functioning.
- D. The alcohol evaporator prevents ice formation but doesn't affect gauge readings directly.
Supply Pressure Gauges
Instruments that display the amount of air pressure available in the primary and secondary air tanks of an air brake system.
- Indicate air pressure in storage tanks.
- Essential for monitoring system health.
- Separate gauges for dual air systems.
Memory trick: Gauges Guide Drivers, showing the air's power.