The governor cuts in (starts the compressor pumping) at approximately 100 PSI. This means when air pressure drops to around 100 PSI during normal use, the compressor begins refilling the tanks.
The CDL (Commercial Driver License) exam tests your knowledge of commercial driving rules, safety procedures, and vehicle operation. You must score 80% or higher to pass the written knowledge test. The exam covers general knowledge, air brakes, combination vehicles, and various endorsements.
This question is from the Class B CDL Air Brakes Test #1 section. Practice with more questions from this category to build confidence before taking the official DMV test.
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