NU Air Brake Test 6 2025

1. Why is an air dryer needed in an air brake system?
2. Upon driver releasing the treadle in an air brake system, to where does the air get directed?
3. What influences the quantity and size of reservoirs on a vehicle with an air brake system?
4. What function does the slack adjuster perform in an air brake system?
5. What does it mean if the safety valve must relieve pressure in an air brake system?
6. Is it necessary to inspect automatic reservoir drain valves every day in an air brake system?
7. Where would one typically find the brake chamber mounted in a vehicle?
8. Where does the pressurized air go as the compressor's piston approaches its peak stroke in an air brake system?
9. What is an alternate term for the supply reservoir in an air brake system?
10. What function does the heater element in the purge valve perform in an air dryer?
11. How is the push rod linked to the slack adjuster in an air brake system?
12. What could be a possible outcome if sludge accumulated in the bottom of the air brake system's tank?
13. What circumstances would prevent a compressor from being able to increase air pressure from 50 to 90 psi within three minutes?
14. At what pressure is a safety valve normally set in an air brake system?
15. What happens to the heated air from the compressor as it cools down in the supply reservoir?
16. What is the crank arm-type lever the push rod is connected to known as in an air brake system?
17. What causes the air in the air brake system's cylinder to compress?
18. How is a brake chamber in an air brake system separated internally?
19. Whereabouts in the air brake system would one typically install an air dryer?
20. What purpose does a safety valve serve in an air brake system?
21. What distinguishes the front axle brake chambers from the rear axle brake chambers in an air brake system?
22. How frequently should the tanks in an air brake system be drained?
23. What happens if there's a leak in the diaphragm of a brake chamber in the air brake system?
24. What's another term for an automatic reservoir drain valve in an air brake system?
25. What is the reason for installing the brake chamber and slack adjuster on the backing-plate of a front axle assembly?
26. What are some advantages of air-over-hydraulic brake systems?
27. Who is usually responsible for manual adjustment of wedge brakes?
28. Which are not usually found in commercial vehicles?
29. Which of these factors would not cause an automatic slack adjuster to fail in maintaining the proper slack?
30. How can drivers track service tank air pressures?
31. What air brake system doesn't necessitate an air brake endorsement?
32. What's a type of low-pressure warning device used predominantly in old vehicles?
33. Which statement is incorrect? Air over hydraulic brake systems were created for medium-weight vehicles because...
34. What psi triggers the low-pressure indicator light or alarm due to overuse or leaks?
35. Is it necessary to check automatic slack adjusters?
36. An air-over-hydraulic brake system is most alike to which system?
37. What must the low-pressure warning system comprise of?
38. What does the stoplight switch do?
39. What does the air line from the foot valve to the relay valve function as?
40. When the warning system is triggered, what action must a driver take?
41. Why is a quick release valve necessary in the braking system?
42. Can a device showing application air pressure be added to the dashboard when brakes are applied?
43. What should be the maximum angle between the push rod and the arm of the slack adjuster when brakes are fully applied?
44. What determines the amount of heat the brakes can absorb and radiate into the surrounding air?
45. Which is false? Extremely unreliable brake performance can come from...
46. When the slack adjusters turn the S-cams, what happens?
47. On manual slack adjusters, the adjusting bolt is turned until the brake linings touch the drums and then backed off by how much?
48. Where is the one-way check valve installed?
49. Which of these could cause brake fading or the reduction in braking power occur?
50. Where is a relay valve usually installed?