Home › CDL Practice Tests › Combination Vehicles Questions › Question 208
Why must you chock the wheels and use care when testing spring brakes on a combination during inspection?
- A.Chocks are only needed for vehicles under 10,000 pounds
- B.When air pressure is released, the spring brakes are what hold the vehicle, and testing them removes that hold on the tested unit
- C.Spring brakes never actually hold a loaded trailer
- D.Testing spring brakes requires removing the wheels
Correct answer
B. When air pressure is released, the spring brakes are what hold the vehicle, and testing them removes that hold on the tested unit
Why
Every air brake test that dumps pressure is trading away the very brakes that keep the outfit parked. Chocks make sure a test on a grade, or a helper's mistake, does not turn into a rollaway.
Manual topic: Combination Vehicles - Air Brake Tests · From the Combination Vehicles practice bank (CV-208).