Question of the Day:
Failure to perform all three components of the air brake check correctly will result in:
A. Automatic failure of the vehicle inspection test.
B. An increase in time on the road.
C. A don’t know, won’t hurt me attitude.
Answer: A. Automatic failure of the vehicle inspection test.
Safety is not only smart, it’s the law. To quote the publicsafety.utah.gov/dld/documents/2010CDLDRIVERMANUAL:
Air Brake Check (Air Brake Equipped Vehicles Only) Failure to perform all three components of the air brake check correctly will result in an automatic failure of the vehicle inspection test. Air brake safety devices vary. However, this procedure is designed to see that any safety device operates correctly as air pressure drops from normal to a low air condition. For safety purposes, in areas where an incline is present, you will use wheel chocks during the air brake check. The proper procedures for inspecting the air brake system are as follows:
Shut off the engine, chock your wheels, if necessary, release the tractor protection valve and parking brake (push in), fully apply the foot brake and hold it for one minute. Check the air gauge to see if the air pressure drops more than three pounds in one minute (single vehicle) or four pounds in one minute (combination vehicle).
Begin fanning off the air pressure by rapidly applying and releasing the foot brake. Low air warning devices (buzzer, light, flag) should activate before air pressure drops below 60 psi.
Continue to fan off the air pressure. At approximately 40 psi on a tractor-trailer combination vehicle, the tractor protection valve and parking brake valve should close (pop out). On other combination vehicle types and single vehicle types, the parking brake valve should close (pop out).
http://publicsafety.utah.gov/dld/documents/2010CDLDRIVERMANUAL-Draft.pdf
http://www.crengland.com/truckdrivingschools/index.jsp?page=timeline