MB Air Brake Test 14 2025

1. When the ABS begins to operate, your immediate reaction should be?
2. Can tractors and trailers equipped with ABS be combined with those lacking ABS without affecting the ABS functionality?
3. Which of these is not a part of the basic configuration of an ABS?
4. What is Automatic Traction Control (ATC)?
5. If the primary circuit fails and a brake application is made, where is control air from the foot valve directed to?
6. In a tractor and trailer combination with spring parking brakes, what happens when the spring parking brake control valve is closed?
7. Which system shares many the same sensing and control components with the automatic traction control (ATC) system?
8. In a vehicle equipped with Automatic Traction Control (ATC), how is the driver alerted when wheel slip is detected?
9. What does the ABS do when it detects a wheel locking up during a brake application?
10. The spring parking brakes with a modulator valve perform how many functions?
11. When a brake application is made and the system detects a wheel locking up, how does the ECU respond?
12. Where can the system warning light for trailers with ABS typically be found?
13. What best describes an anti-lock brake system (ABS)?
14. Are old and new tractor and trailer systems interchangeable with respect to those with spring parking brakes?
15. In a vehicle equipped with an air brake system with manual slack adjusters, can the brake pedal be pumped to compensate for brakes that are out of adjustment?
16. In a vehicle equipped with Automatic Traction Control (ATC), what happens if wheel slip is detected while the vehicle's cruise control is set?
17. As the air pressure drops below 85 psi, what happens to the spring parking brakes?
18. How is electronic engine control activated?
19. When does differential braking occur?
20. If air in the primary circuit is lost, the spring-brake modulator valve allows the driver to still use the brake pedal to apply the brakes. Until when can brake applications be repeated?
21. Does the air brake system remain the same even with the addition of ABS components?
22. Is it possible for a trailer with a basic air brake system to be towed by a tractor with a dual air brake system?
23. Which of the following typically causes brake failures?
24. Select the incorrect steps when adjusting S-cam brakes with manual slack adjusters.
25. What should you do at your first stop after adjusting the brakes?
26. When doing a pre-trip inspection, at how many psi should the warning devices function?
27. You can stay aware of the condition of your vehicle's braking system by doing all of these EXCEPT
28. What is not a step to determine if an S-cam brake with manual or automatic slack adjusters needs adjustment?
29. After two inches of push rod stroke, what happens to the force available at the push rod?
30. When brakes are adjusted by slack adjusters, where do the shoes move?
31. Identify the incorrect statement about the steps to determine if an S-cam brake with manual slack adjusters needs adjustment.
32. When testing the low air pressure warning devices, why should you release the spring parking brake after pressure builds to 90 psi?
33. After adjusting the manual slack adjuster, by what amount should the adjustment bolt be backed off?
34. How long should the pre-trip air brake inspection take?
35. Why is brake shoe adjustment necessary?
36. Who should you consult regarding the adjustment procedure for various air disc brakes?
37. If the S-cam brakes with automatic slack adjusters are severely out of adjustment, who should inspect them?
38. What is not typically part of a brake test?
39. During a leakage check, the pressure should not fall more than how many psi per minute?
40. All of these can negatively affect a vehicle's braking ability EXCEPT
41. When checking the S-cam brake adjustment with a manual slack adjuster, what should you ensure?
42. What is the most reliable method to ensure your vehicle brakes are properly adjusted?
43. What is not checked during an in-service check before a long or steep downgrade?
44. When the brakes are out of adjustment, braking efficiency is reduced by all of these EXCEPT
45. When is it recommended to adjust automatic slack adjusters by hand?
46. How frequently should you check automatic slack adjusters?
47. Who has the responsibility to ensure that the vehicle has safe, properly adjusted brakes?
48. Identify the incorrect statement. During a pre-trip inspection, you should check the drive belt and pulleys for...
49. For S-cam brakes, what could increase the overall push rod travel?
50. What is not a required step while performing a manual wedge brake adjustment?