WV CDL AIR BRAKES PRACTICE TEST

21. Why must air tanks be drained?
Water can freeze in cold weather and cause brake failure.
The low boiling point of water reduces braking power.
Water and oil reduce the air pressure.
To keep from fouling the air compressor oil.
22. If your vehicle has dual parking control valves, you can use pressure from a separate tank to:
release the spring brakes so you can move the vehicle in an emergency.
park better.
balance the service brakes while you are parked.
None of the above.
23. When driving in hot weather, drivers should inspect tires:
every 3 hours or every 75 miles.
every hour or every 50 miles.
every 2 hours or every 100 miles.
every 4 hours or every 200 miles.
24. Parking brakes are:
not required on trailers.
required on all vehicles.
not required on commercial vehicles with air brakes.
not required on buses.
25. The heavier the vehicle:
the less work the brakes must do to stop it.
the more work the brakes must do to stop it.
the higher the center of gravity will be.
None of the above.
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