CDL Air Brakes TestUsing Air BrakesEasy
During a pre-trip inspection, a commercial driver checks the air tanks (reservoirs). What is the primary purpose of these tanks in an air brake system?
- ATo store compressed air for immediate and emergency use.
- BTo activate the parking brake automatically.
- CTo regulate the air pressure going to the brake chambers.
- DTo filter moisture and oil from the compressed air.
Show answer & explanationAnswer & explanation
Correct answer: A. To store compressed air for immediate and emergency use.
The air tanks, or reservoirs, are the storage units for compressed air within the air brake system. They hold a reserve of air pressure ready for immediate use by the service brakes, parking brakes, and other air-operated accessories, ensuring that there's always enough air for multiple brake applications.
Why the other options are wrong
- B. The parking brake is activated by spring pressure when air pressure drops, but the tanks' purpose is storage, not direct activation.
- C. Pressure regulators and valves control air pressure to the brake chambers, not the tanks.
- D. The air dryer (or alcohol evaporator) is responsible for filtering moisture and oil, not the tanks themselves.
Air Tanks (Reservoirs)
Components of an air brake system that store compressed air for use by the brakes and other air-powered accessories.
- Hold a reserve of air pressure.
- Essential for multiple brake applications.
- Must be drained regularly to remove contaminants.
Memory trick: Tanks are like batteries, holding air for when you need it.