An air brake system on a truck tractor is actually three separate braking systems sharing components. Which three systems make up a vehicle's air brake system?
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Correct!
Correct. The AAMVA CDL Manual defines air brakes as really three different braking systems: the service brake (applies/releases brakes via the pedal for normal driving), the parking brake (applies/releases the parking brakes via the parking control, using spring brakes), and the emergency brake (uses parts of the service and parking systems to stop the vehicle if there is a brake system failure). This is the nomenclature tested under 49 CFR 383.111(b)(1).
49 CFR 383.111(b)(1) (general air brake system nomenclature)
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Not quite.
Incorrect. 'Primary' and 'secondary' describe the two halves of a dual air brake system (one circuit for the front axle brakes, one for the rear), not the three systems that make up air brakes overall. There is no 'tertiary' circuit in the AAMVA nomenclature.
The correct answer is A: Service brake, parking brake, and emergency brake.
49 CFR 383.111(b)(1) (general air brake system nomenclature)
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Not quite.
Incorrect. 'Foundation brakes' refers to the physical brake hardware at each wheel (drums, shoes, S-cam, etc.), not one of the three functional systems. 'Supply brake' and 'control brake' are not terms used in the manual's nomenclature.
The correct answer is A: Service brake, parking brake, and emergency brake.
49 CFR 383.111(b)(1) (general air brake system nomenclature)
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Not quite.
Incorrect. S-cam, wedge, and disc are the three types of foundation brake hardware used at the wheels to apply friction against the drum or rotor. They are not the three functional braking systems (service, parking, emergency).
The correct answer is A: Service brake, parking brake, and emergency brake.
49 CFR 383.111(b)(1) (general air brake system nomenclature)