Q
A shut-off valve:
Combination Vehiclesmedium
AControls the vehicle's speed
BPrevents air from escaping an air brake system
CRegulates fuel intake
Detailed Explanation
The correct answer is "Prevents air from escaping an air brake system". This is based on federal CDL regulations and safety standards.
Correct Answer: Prevents air from escaping an air brake system
Ready to practice for real?
Take our free, full-length Combination Vehicles practice test. Simulates the actual DMV exam with timed questions.
Start Practice TestRelated Questions
46. You have pushed the trailer air supply valve. You should not back a tractor under a trailer until the whole air system is:
combination-vehiclesmedium
When backing a trailer, how should you turn the steering wheel?
combination-vehicleseasy
19. When backing under a tractor under a trailer you should expect:
combination-vehiclesmedium
14. In normal driving, some drivers use the hand valve before applying the brake pedal to prevent a jackknife. Which of these statements is true?
combination-vehiclesmedium
27. The fifth wheel locking lever is not locked after the jaws close around the kingpin. This means that:
combination-vehiclesmedium