DC CDL AIR BRAKES PRACTICE TEST

11. When checking air brakes on combination vehicles, which of the following is NOT part of checking that air flows to all trailers?
Opening the emergency line shut-off valve at the rear of the last trailer.
Going to the rear of the rig.
Pulling tractor forward until the fifth-wheel comes out from under the trailer.
Using the trailer handbrake to provide air to the service line.
12. Excessive use of the service brakes results in overheating and leads to:
low air pressure.
reduction of the brake drums.
brake fade.
poor traction.
13. When should you downshift automatic transmissions?
When going down steep grades.
When you start to get drowsy.
Watch your tachometer, and downshift when your engine reaches the top of the range.
When you want to go faster.
14. If you get stuck on railroad tracks, you should:
stay in the vehicle and call for help.
check the engine compartment quickly.
get out of the vehicle and away from the tracks.
have a helper push your vehicle.
15. In newer vehicles with air brakes, you put on the parking brake:
moving the orange push-pull lever to the right.
using a P-shaped, yellow control knob.
using a diamond-shaped, yellow, push-pull control knob.
placing the transmission in Park.
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