Louisiana CDL — Air Brakes Practice Test 1

11.On vehicles with dual parking control valves and a separate air tank to release the spring brakes, why must you plan your moves carefully?

The separate tank refills only when the vehicle is parkedThe spring brakes will release just once each dayThe separate tank holds only enough air to release the spring brakes a few timesThe valve locks out the service brakes while moving

12.When checking manual slack adjusters, about how much movement means they probably need adjustment?

Any movement at allAbout one quarter inchMore than roughly one inch of play at the push-rod connectionMore than six inches

13.Total stopping distance for an air-brake vehicle is made up of which factors?

Perception, reaction, and braking distance onlyReaction, brake lag, and skid distancePerception, reaction, brake lag, and braking distancePerception, brake lag, and coasting distance

14.If the ABS malfunction lamp stays on after the bulb check or comes on while driving, what does it likely mean?

The tanks need drainingThe parking brakes are engagedABS may no longer be working at one or more of the wheelsThe compressor has reached cut-out

15.What must you always do before leaving your vehicle unattended?

Drain the air tanks completelyRelease the spring brakesApply the parking brakes or chock the wheelsRev the engine to build pressure

16.In an air brake system, the air compressor is responsible for what?

Warning the driver when tank pressure gets lowReleasing the parking brakes when you push the control inRemoving water and oil from the storage tanksPumping air into the storage tanks that feed the brakes

17.If the air compressor has its own supply of oil, what should you do before driving?

Check the compressor's oil levelDrain all of the air tanks completelyFill the alcohol evaporatorManually adjust each slack adjuster

18.Where is the yellow ABS malfunction lamp located on a trailer?

On the instrument panel in the cabOn the left side, at the front or rear cornerOn the right rear bumperInside the engine compartment

19.What must you do before pulling on the slack adjusters to check them?

Fully apply the foot brake and leave the engine runningPark on level ground, chock the wheels, and release the parking brakesBuild pressure up to 150 psiSet the modulating valve to full

20.In a drum brake, what actually slows the vehicle?

Air pushing directly against the outside of the wheelThe slack adjuster gripping the axleThe brake shoes and linings pressing against the inside of the drumA power screw clamping a rotor