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How does an engine brake (such as a compression release brake) help on a downgrade?
- A.It adds power for climbing
- B.It turns the engine into a retarding device that holds speed without heating the service brakes, preserving them for when they are truly needed
- C.It replaces the service brakes for stopping at lights
- D.It works by applying the trailer brakes
Correct answer
B. It turns the engine into a retarding device that holds speed without heating the service brakes, preserving them for when they are truly needed
Why
By using engine compression to slow the vehicle, the retarder handles the steady speed control that would otherwise cook the brake drums. The service brakes then stay cool and available for full stops and emergencies at the bottom.
Manual topic: Engine Controls - Engine Brake · From the General Knowledge practice bank (GK-369).