AB Air Brake Test 6 2025

1. If the weight of a vehicle is doubled, how much braking power is required?
2. For which licensing class is an air brake endorsement not required?
3. What is transformed into heat energy by the brakes?
4. Are students expected to prove they can confirm correct brake adjustment during the course?
5. Who has the responsibility of administering the air brake knowledge test?
6. How much would the braking force need to increase if both weight and speed of a vehicle are doubled?
7. What happens to the heat generated in the brakes during braking?
8. Besides air pressure purge, what else is it referred to as?
9. At what pressure value does the air brake system's governor cut out?
10. From where is the air compressor directly powered?
11. What is the main function of air dryers in an air brake system?
12. When would the contaminants drain most effectively from an air brake system?
13. Which brake system generates more force?
14. What is the purpose of a lanyard pull cable in an air brake system?
15. What is the role of Inline Alcohol Injectors in an air brake system?
16. How is compressed air defined in the context of air brakes?
17. What component regulates the air compressor as needed to maintain air pressure?
18. How does the air brake system compensate for a small air leak?
19. Which of these is not a reason for the slow build-up of air pressure?
20. Who should ensure the proper functioning of air brakes?
21. Which statement is incorrect about air brakes?
22. How is air pressure typically measured in an air brake system?
23. The governor cuts in at _______ below the cut–out pressure.
24. Where are the drain valves located in an air brake system?
25. Where would the driver be when control and quick release valves exhaust forcefully?
26. How is the air pressure monitored in an air brake system?
27. What does a kilopascal (kPa) measure in air brake systems?
28. After running the engine at 1200 rpm, how long will it take the compressor to build from 50 to 90 PSI?
29. Is it required to wear personal protective equipment when servicing air brake systems?
30. Which of the following statements is not true about air brakes?
31. What is an alternative name for the supply tank in air brake systems?
32. Which is false about the supply tank in air brake systems?
33. How often should the supply tanks in an air brake system be drained?
34. What is the role of the supply circuit in an air brake system?
35. Why is the presence of safety valves necessary in an air brake system?
36. Before performing any air brake system maintenance, should the air tanks be drained?
37. After air is pressurized by the air compressor, where is it pumped to?
38. What is the function of brake chambers in a commercial vehicle's braking system?
39. What is the primary role of a check valve in a commercial vehicle's air brake system?
40. Why is it important to only use the right kind of air brake antifreeze in the alcohol evaporator or alcohol injectors of the air brake system?
41. How many air lines typically connect to the trailer in an air brake system?
42. In an air brake system, does each axle group in a power unit have its own independent service brake circuit?
43. Besides the steering axle, for which other axle does a power unit have a service circuit?
44. Upon what is a service tank's capacity established?
45. What is the most common size of brake chambers for load-bearing axles?
46. What component is not part of the service brake circuit?
47. How would you know if a trailer should not have alcohol-based antifreeze?
48. What is installed near the brake chambers to cut down on lag time?
49. How many full-service brake applications should the capacity of the air tank be able to sustain?
50. At what point can the tanks in an air brake system be properly drained?
51. On manual slack adjusters, the adjusting bolt is turned until the brake linings touch the drums and then backed off by how much?