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Why are air brakes preferred over hydraulic brakes for very heavy combination vehicles?
- A.Compressed air can supply large brakes on both tractor and trailer, and a leak does not instantly remove all braking fluid
- B.Air brakes need no inspection or maintenance
- C.Air brakes stop a truck in a shorter distance than a car
- D.Air brakes work even with the engine removed
Correct answer
A. Compressed air can supply large brakes on both tractor and trailer, and a leak does not instantly remove all braking fluid
Why
Air scales well to trailers through simple hose connections and provides the force large drums require. The dual-circuit and reservoir design also gives a reserve that a single hydraulic circuit cannot match for heavy combinations.
Manual topic: Air Brakes - Dual Air Brake Systems · From the Air Brakes practice bank (AB-025).