CDL Air Brakes Endorsement II Practice
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- 1.What is a dual air brake system?
- A.
A two brake system, one operates the front brakes and one operates the back brakes.
- B.
A two braking system, one for each side of the vehicle.
- C.
A two braking system, one for daytime and one for nighttime driving.
- 2.What are the slack adjusters?
- A.
It is the space between the back wheels.
- B.
It is an adjusting nut on the backside of the brake drum used for adjusting the brakes.
- C.
It is an adjusting nut under the cab to adjust the springs.
- 3.How can you check the slack adjuster?
- A.
Park on level ground, turn off parking brakes, pull hard on each slack adjuster. It shouldn't move more than one inch.
- B.
Park on level ground, turn off parking brake and press brake pedal.
- C.
Park on an incline and see if the vehicle rolls.
- 4.How can you test the low pressure warning signal?
- A.
While the engine is running, step on and off the brake pedal.
- B.
Shut off the engine and see if the air pressure leaks down.
- C.
Shut off the engine with enough air pressure, turn on the electrical power and step on and off the brake pedal until the low air pressure warning signal comes on.
- 5.What can you check to see if the spring brakes come on automatically?
- A.
Step on and off the brake, with the engine off, the parking brake knob should pop out when air pressure falls between 20-40 psi.
- B.
Get under the vehicle and pull on the spring brakes.
- C.
Turn on the engine and pump the brake pedal down to the floor.
- 6.What are the maximum leakage rates?
- A.
Less than four psi in one minute for single vehicles and less than eight psi in one minute for combination vehicles.
- B.
Less than two psi in one minute for single vehicles and less than three psi in one minute for combination vehicles.
- C.
Less than six psi for all vehicles.
- 7.Should you ever leave your vehicle unattended without applying parking brakes or chocking the wheels?
- A.
Yes
- B.
No
- 8.If you are away from your vehicle only a short time, you don't need to use the parking brake.
- A.
True
- B.
False
- 9.How often should you drain air tanks?
- A.
Daily
- B.
Weekly
- C.
Monthly
- 10.The use of brakes on a long steep downgrade is only a supplement to the braking effect of the engine.
- A.
True
- B.
False
- 11.What factors can cause brakes to fade or fail?
- A.
Not pressing the brake pedal hard enough.
- B.
Over heating, low air pressure, and not relying on the engine braking effect.
- C.
Not taking your foot off the accelerator pedal.
- 12.Why should you be in the proper gear before starting down a hill?
- A.
So you only have to apply the brake just hard enough to feel a definite slowdown
- B.
So you don't have to shift gears going downhill.
- C.
So you can go through the gears on the way down.
- 13.If oil and water collect in the air tanks what can happen to the brakes?
- A.
The brakes could heat up.
- B.
The brakes could fail.
- C.
The brakes could lock up.
- 14.What is the purpose of an alcohol evaporator?
- A.
So you don't have to drain the air tanks as often.
- B.
To have a drink available if you get thirsty.
- C.
To reduce the risk of ice in the brake valves and other parts in cold weather.
- 15.What is another name for controlled braking?
- A.
Steady braking
- B.
Squeeze braking
- C.
Hard braking
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