DMV Class B License Test: Air Brakes

DMV Class B License Test: Air Brakes

Endorsement Exam Graded A+

Excessive use of the service breaks results in overheating, which can lead to:

a) Improper adjustment of the S-cam

b) Increased contact between the brake drums and brake linings

c) Expansion of the brake drums - ANSWER-c) Expansion of the brake drums

If air pressure does NOT build up to normal within the correct amount of time:

a) You should be ready to use your parking brake to help stop

b) The alcohol container may be low

c) Your air pressure may drop too low during driving - ANSWER-c) Your air pressure

may drop too low during driving

If you must make an emergency stop, you should brake so you:

a) Use the hand brake before the brake pedal

b) Use the full power of the brakes to lock them

c) Can steer and your vehicle stays in a straight line - ANSWER-c) Can steer and your

vehicle stays in a straight line The proper method of braking when going down long and/or steep grades, after selecting the proper gear, is to brake until your speed is about ___ MPH below your "safe" speed, then release your brakes

• 5
• 10
• 15 - ANSWER-a) 5

Your bus or truck has a dual air brake system. If a low air pressure warning comes on only for one system, what should you do?

a) Reduce your speed and drive to the nearest garage for repairs 1 / 2

b) Reduce your speed and test the remaining system while driving

c) Stop and safely park. Continue only after the system is fixed - ANSWER-c) Stop and

safely park. Continue only after the system is fixed The driver must be able to see a warning before air pressure in the service tanks falls below ___ psi.

• 50
• 60
• 80 - ANSWER-b) 60

The parking or emergency brake on a heavy vehicle can only be held in position by

something cannot leak away, like:

a) Spring pressure

b) Air pressure

c) Hydraulic pressure - ANSWER-a) Spring pressure

Before driving a truck or bus with a dual air brake system, the pressure in each system should be at least ___ psi.

• 80
• 100
• 120 - ANSWER-b) 100

The brake system that applies and releases the brakes when the driver uses the brake pedal is the ___ brake system.

a) Emergency

b) Service

c) Parking - ANSWER-b) Service

Controlled braking:

a) Involves locking the wheels for short periods of time

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