RAINING FOR OVER 45 YEARS

Transcription

1 CDL PRACTICE TEST CDL AIR BRAKES PRACTICE TEST Multiple choice (p. 1-5) Answer key (p. 6-7) Scorecard (p. 8) Learn Practice Drive

2 1. The application air gauge shows: a. Total air pressure in air system b. Amount of pressure currently being applied by brake pedal c. How much air had been used 2. If you experience a rapid air loss and the service brake system is no longer working, which brake system is used to stop the vehicle? a. Parking brake system b. The one way check valve system c. Service brake system d. Emergency brake system 3. Air tanks should be drained when: a. Daily b. Weekly c. At the end of the trip d. Never, it is done by the mechanic 4. If you experience a sudden drop in the air system you should: a. Continue driving it is of little importance b. Continue driving but only to the next repair shop c. Keep your eye on the gauge and see if it will build the pressure back up d. Stop immediately when it is safe to do so

3 5. When a driver steps on the brake pedal, what brake system is he using? a. Service brakes b. Emergency brakes c. Parking brakes d. None of the above 6. Emergency brakes are activated: a. By the brake pedal b. By the foundation brake system c. By a loss of air pressure 7. Which of the following is found on most commercial vehicles? a. Wedge and drum b. Disc c. S - cam drum d. None of the above 8. When in operation with the air brake system working properly, the brakes are held away from the drum by: a. Spring pressure b. Air pressure c. Hydraulic pressure

4 9. When should the front brake limiting valve be used: a. Never b. On dry roads only c. On wet roads d. Whenever the driver feels it is needed 10. A combination vehicle, with engine off and brakes applied, should not lose more than: a. 3 PSI in one minute b. 2 PSI in one minute c. 4 PSI in one minute d. 4 PSI in 30 seconds 11. Stab braking means: a. Brake hard until wheels lock up then release until wheels begin to roll again b. Brake hard, but not enough to lock wheels c. Light, steady pumping action 12. When should you use the snub breaking technique on a long downgrade? a. If brakes are properly adjusted b. If brake linings are made out of asbestos c. If brakes are properly adjusted and vehicle is in proper gear d. When your company authorizes it

5 13. The brake pedal a. Controls the speed of the air compressor b. Is seldom used, compared to hydraulic systems c. Controls the air pressure applied to put on the brakes d. Is connected to slack adjusters by a series of rods and linkage 14. Parking brakes of trucks can be legally held by pressure. a. Spring b. Fluid c. Air d. Atmospheric 15. The holding power of the spring brakes a. Increases when they are hot b. Depends on the adjustment of the service brakes c. Is not affected by the condition of the service brakes d. Can only be tested by highly-trained brake service people 16. The driver must be able to see and or hear a low air pressure warning which is activated when the pressure in the service air tanks fall below PSI: a. 20 b. 40 c. 60 d. 80

6 17. A supply pressure gauge shows: a. Air available in the air tanks b. Pressure being applied by foot brake c. Amount of air in brake chamber d. How fast the compressor is filling the tanks 18. When going down a long downgrade, the gear you should be in is a. The same one you went up in b. A higher gear than the one used going up the grade c. A lower gear than the one used going up the grade d. It doesn t make any difference if your truck is equipped with an engine brake 19. Air brakes take more time to work than hydraulic brakes due to: a. Brake lag b. Driver s perception time c. The working of the one-way check valve 20. Effective braking distance is: a. The distance your vehicle travels after you see the hazard b. The distance your vehicle travels after you react c. The distance your vehicle travels after you step on the brake pedal d. The distance your vehicle travels after brakes have been applied

7 ANSWER KEY 1. The application air gauge shows: b. Amount of pressure currently being applied by brake pedal 2. If you experience a rapid air loss and the service brake system is no longer working, which brake system is used to stop the vehicle? d. Emergency brake system 3. Air tanks should be drained when: a. Daily 4. If you experience a sudden drop in the air system you should: d. Stop immediately when it is safe to do so 5. When a driver steps on the brake pedal, what brake system is he using? a. Service brakes 6. Emergency brakes are activated: c. By a loss of air pressure 7. Which of the following is found on most commercial vehicles? c. S - cam drum 8. When in operation with the air brake system working properly, the brakes are held away from the drum by: b. Air pressure 9. When should the front brake limiting valve should be used: A.) Never 10. A combination vehicle, with engine off and brakes applied, should not lose more than: c. 4 PSI in one minute

8 11. Stab braking means: a. Brake hard until wheels lock up then release until wheels begin to roll again 12. When should you use the snub braking technique on a long downgrade? c. If brakes are properly adjusted and vehicle is in proper gear 13. The brake pedal: c. Controls the air pressure applied to put on the brakes 14. Parking brakes of trucks can be legally held by pressure: a. Spring 15. The holding power of the spring brakes b. Depends on the adjustment of the service brakes 16. The driver must be able to see and or hear a low air pressure warning which is activated when the pressure in the service air tanks fall below PSI: c A supply pressure gauge shows: a. Air available in the air tanks 18. When going down a long downgrade, the gear you should be in is: c. A lower gear than the one used going up the grade 19. Air brakes take more time to work than hydraulic brakes due to: a. Brake lag 20. Effective braking distance is: d. The distance your vehicle travels after brakes have been applied

9 SCORECARD Number correct Number incorrect Percent Pass/Fail? 1 st attempt 2 nd attempt 3 rd attempt Most states require you answer at least 70% of the questions correctly to pass