Practice question

Under PennDOT CDL Manual Section 5, what is a dual air brake system?

A system that uses two compressors
A system with two completely separate air systems (primary and secondary), each controlling brakes on different axles
A system that uses both air and hydraulic fluid
A system with air-cooled drums

Answer: B — A system with two completely separate air systems (primary and secondary), each controlling brakes on different axles

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