Home › CDL Practice Tests › Air Brakes Questions › Question 75
With the brakes fully applied and the engine off, what is the maximum allowable leakage for a single vehicle?
- A.No more than 2 psi per minute with no stabilization allowed
- B.No more than 3 psi per minute after the initial pressure drop stabilizes
- C.No more than 8 psi per minute
- D.Pressure should not drop at all for ten minutes
Correct answer
B. No more than 3 psi per minute after the initial pressure drop stabilizes
Why
The applied limit for a single vehicle is 3 psi per minute, one psi above its static limit because chambers and treadle seals are now pressurized. A faster drop points to a leaking chamber diaphragm or valve.
Manual topic: Air Brakes - Air Leakage and Brake Tests · From the Air Brakes practice bank (AB-075).