Practice question

During Maryland CDL combination-vehicle preparation, what should a driver remember about the trailer air supply control?

Use the trailer hand valve for normal stops
Drive with trailer air pressure faults
Assume ABS permits tailgating or poor brake checks
The red trailer air supply control supplies trailer air when pushed in and shuts it off when pulled out.

Answer: D — The red trailer air supply control supplies trailer air when pushed in and shuts it off when pulled out.

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