Home › CDL Practice Tests › Air Brakes Questions › Question 17
What is the purpose of the one-way check valves between air tanks in a dual system?
- A.They prevent air from flowing back and draining a good tank if another tank or line fails
- B.They increase pressure beyond the safety valve setting
- C.They allow the driver to mix air between tanks at will
- D.They replace the need for drain valves
Correct answer
A. They prevent air from flowing back and draining a good tank if another tank or line fails
Why
Check valves isolate the reservoirs from each other while still letting the compressor charge them. That isolation is a core reason one leak does not empty the entire system.
Manual topic: Air Brakes - Air Brake System Components · From the Air Brakes practice bank (AB-017).