CDL Written Test Air Brakes Quiz
Try the Online Air Brakes Quiz to view the answers.
CDL Test Questions
1. How can you prevent water and oil from building up in the air storage tanks?
( )Drain your air tanks daily.
( )Make sure all air lines have a secure connection.
( )It is not necessary to drain your air tanks, water and oil will be automatically expelled.
2. The air compressor____.
( )is attached to the engine and pumps air into the storage tanks. ( )pumps air into the storage tanks through the foot brake control.
( )controls the temperature of the cab in hot weather.
3.The most common type of air brake system is the__ .
( )S- Cam
( )Wedge Brake
( )Disc Brake
4. Which statement best defines the air governor?
( )The air governor controls when the air compressor will pump air into the air storage tanks. ( ) The air governor controls how much air pressure is released from the foot brake.
( )The air governor controls how much air pressure is applied to the brake drum.
5. The gauge that measures the amount of air in the storage tanks is called the air application gauge.
( )True ( )False
6. All air brake vehicles must have a low air pressure warning signal. What is it?
( )A red light, buzzer or flag that warns the driver when air pressure falls below 60 psi. ( )A red light, buzzer or flag that warns the driver when air pressure falls below 100 psi.
( )A red light, buzzer or flag that warns the driver when air pressure falls below 20 psi.
7. Front wheel brakes are good under all conditions.
( )True ( )False
8. Which is the best definition of spring brakes?
( )Spring brakes hold the vehicle in place when parked and act as an emergency brake system if air pressure is removed. ( )Spring brakes are different than air brakes. When you place your foot on the brake pedal; powerful springs rotate and contract thus applying the brake shoes to the disc or drum.
( )Spring brakes use a combination of air and springs to stop the vehicle.
9. When will your ABS brakes activate?
( )ABS brakes only activate when your wheels are about to lock up. ( )ABS stands for Always Brake System. Your ABS brakes are always active giving you the greatest stopping power.
( )ABS brakes activate after your drive wheels have locked up.
10. Which is the best definition of a dual air brake system?
( )A dual air brake system has two separate systems. One system operates the brakes on the front axle and one system operates the brakes on the rear axle. Both systems supply air to the trailer.
( )A dual air brake system has two separate systems. One operates the brakes on the trailer and one operates the brakes on the tractor.
( )A dual air brake system consists of the regular braking system and the ABS system.
11. When driving with a dual air brake system you should:
( )Have a minimum of 100 psi, watch both gauges and pay attention to the low air warning light or buzzer. ( )Use the hand brake and the foot brake of the dual system in tandem.
( )Make sure the rear axle has a minimum of 100 psi since it has spring brakes. The front axle (without spring brakes) does not have a minimum air pressure.
12. Which is the correct procedure for checking slack adjusters on s-cam brakes?
( )Park on level ground and chock the wheels, release the parking brakes, pull on each slack adjuster. Slack adjusters with more than 1 inch of free play need adjustment.
( )Park on level ground and chock the wheels, pull on each slack adjuster. Slack adjusters with more than 1 inch of free play need adjustment.
( )Park on level ground and chock the wheels, release the parking brakes, pull on each slack adjuster. Slack adjusters with more than 2 inches of free play need adjustment.
Try the Online Air Brakes Quiz to view the answers.
13. How can you test that the low air pressure warning device works?
( )Turn on the key so you have electricity, pump the brake pedal to reduce air pressure. The low air warning light, buzzer or flag should come on before 60psi.
( )Apply the parking brake fully, if the pressure falls more than 3 psi.
( )Turn on the key so you have electricity, pump the brake pedal to reduce air pressure. The low air warning light, buzzer or flag should come on between 45-20 psi.
14.When performing the "applied air loss test" how much air pressure loss is acceptable for a single vehicle?
( )3 psi
( )4 psi
( )2 psi
15. What should happen when you bleed the air brake system by pumping the brakes down between 45-20 psi?
( )The low pressure warning signal will activate.
( )The emergency brakes will activate and the parking brake knob will pop out.
( )The static applied air pressure warning system will activate.
16.Brake linings must not be___ (check all that apply).
[ ]must not be soaked with oil or grease.
[ ]excessively thin.
[ ]loose. [ ]red.
[ ]leaking fluid.
17.What should happen when you pump the brakes down between 45-20 psi?
( )The low pressure warning signal will activate.
( )The emergency brakes will activate and the parking brake knob will pop out.
( )The static applied air pressure warning system will activate.
18. How can you test that the service brakes work?
( )Wait for normal air pressure, release the parking brake, move the vehicle forward 5 mph and apply the foot brake. Note any pulling to one side or delayed stopping action. ( )Turn off the motor, release the parking brake, hold your foot on the brake pedal for 1 minute. Note any loss of air pressure.
( )Wait for normal air pressure, pump the brakes down to 85 psi and note that the air compressor builds from 85-100 psi in one minute.
19. ABS brakes gives you added stopping power. Use less than normal braking pressure while stopping.
( )True ( )False
20. The air brake lag effect adds 2 seconds to the total stopping distance formula.
( )True ( )False
21. What is the best definition of brake fade?
( )When the brakes become too hot, they may start to fade. This means you have to apply them harder and harder to get the same stopping power.
( )If the brakes become too hot they will fail and you will not be able to stop the vehicle.
( )When you shut off the motor and release the brakes: if you lose more than 2 psi in one minute you have brake fade.
22. When driving in the mountains, what may happen if you have one or more brakes out of adjustment?
( )Brakes that are out of adjustment will stop doing their share of the work, causing the other brakes to overheat and fade.
( )It may cause a serious air leak in the system. If you lose more than 4 psi in one minute the vehicle will lose braking ability.
( )The low air warning system may activate and the emergency brake system will cause the spring brakes to "pop" out.
23. A vehicle with ABS brakes doesn't need to use the braking effect of the engine if every brake is adjusted.
( )True ( )False
24. What must you do as soon as the low air warning pressure system activates?
( )Drive the vehicle to next and park, place your red reflective triangles in the proper position and call for help.
( )You have enough air in the reserve system to finish up your route. You must notify maintenance and place the vehicle out of service tomorrow.
( )Stop and safely park your vehicle as soon as possible.
25. If you are parked on a flat, level ground it is not necessary to set your parking brakes.
( )True ( )False