cdl air brakes Flashcards

What's on the cards

1. In an air brake system, what does the air compressor governor control?
2. For an air brake system in good condition, the governor lets the air compressor start pumping again at the cut-in level, which is about how many psi?
3. How is the air compressor connected to the engine?
4. If the air compressor on your truck has its own oil supply, when should you check its oil level?
5. Where is the compressed air in an air brake system stored?
6. Why should you drain the water from compressed air tanks?
7. If you do not have automatic tank drains, how often should you drain the oil and water from the air storage tanks?
8. If your air brake system has an alcohol evaporator, what is it there to do?
9. If your vehicle has an alcohol evaporator, what should you do every day during cold weather?
10. Some air brake systems have an alcohol evaporator. What may happen if the unit is not kept filled with alcohol?
11. The safety valve in the first air tank is usually set to open at how many psi?
12. What does the brake pedal do in an air brake system?
13. Repeatedly pressing and releasing the brake pedal (fanning) without need may result in what?
14. What is the most common type of foundation brake on heavy vehicles?
15. When you apply the brakes, the brake shoes and linings are pushed against what?
16. What are the slack adjusters on S-cam brakes?
17. How should you check the free play of the manual slack adjusters on S-cam brakes, and where should you park to do it?
18. What does the air supply pressure gauge show the driver?
19. The application pressure gauge shows how much air pressure you are applying to what?
20. How can you tell that your brakes are fading?
21. All vehicles equipped with air brakes must have what gauge?
22. What does the stop light switch on an air brake vehicle do?
23. True or false: front wheel brakes are good under all conditions.
24. The parking or emergency brakes of trucks and buses can be legally held on by what?
25. During normal driving, what usually holds the spring brakes back?
26. What are spring brakes on an air brake vehicle?
27. What does the braking power of the spring brakes depend on?
28. If the spring brakes are on, when should you push the brake pedal down?
29. What does a modulating control valve let you control?
30. If your truck or bus has dual parking control valves, what can you use the pressure from the separate air tank to do?
31. Which brake system applies and releases the brakes when the driver uses the brake pedal during normal driving?
32. Air brakes combine three different braking systems. They are the service brakes, the parking brakes and the ___ brakes.
33. What is a dual air brake system on a truck or bus?
34. Before driving a truck or bus with a dual air brake system, the air pressure in each system should be built up to at least how many psi?
35. Your truck or bus has a dual air brake system. If the low air pressure warning comes on for only one of the systems while driving, what should you do?
36. If your truck has a dual air system and one of the systems is very low on pressure, what happens?
37. With a properly working dual air brake system, how quickly should air pressure build from 85 to 100 psi?
38. With a single air brake system (on vehicles built before 1975), how should the air pressure build?
39. If the air compressor develops a leak, what keeps the air in the tanks?
40. What is the first thing you should do when the low air pressure warning comes on?
41. How can you test the low air pressure warning signal?
42. How can you check that the spring brakes come on automatically when air pressure in the system drops?
43. With the engine off and the brakes applied, the air loss rate for a straight truck or bus should not be more than how much?
44. With the engine off and the brakes released, a straight truck or bus air brake system should not leak more than how many psi per minute?
45. How should you test the air leakage rate with the brakes released?
46. How should you check that your service brakes are working properly?
47. If you must make an emergency stop in an air brake vehicle, you should brake so that you:
48. What is emergency controlled braking?
49. What is emergency stab braking?
50. Why does air braking take more time than hydraulic braking?
51. What makes the total stopping distance for air brakes longer than for hydraulic brakes?
52. At 55 mph on dry pavement, the air brake lag distance adds about how many feet to your stopping distance?
53. Under ideal conditions, a truck with air brakes going 55 mph would require a stopping distance of about how many feet?
54. Excessive use of the service brakes results in overheating, which can lead to what?
55. True or false: on a long or steep downgrade, using the brakes is only a supplement to the braking effect of the engine.
56. Going down a long, steep grade in the proper gear, you should brake until your speed is about how many mph below your safe speed?
57. You are going down a steep downgrade and have reached your safe speed of 40 mph. You apply the service brakes until your speed drops to how many mph?
58. When should the parking brakes be used on an air brake vehicle?
59. Which of these is NOT a proper time to use the parking brakes on an air brake vehicle?

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