Do You Know How To Use Air Break?

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1. Air compressor cut-in pressure must never be less than?

Explanation

The cut-in pressure of an air compressor refers to the minimum pressure at which the compressor starts running to build up pressure in the system. It is important for the cut-in pressure to be set at an appropriate level to ensure efficient and safe operation of the compressor. A cut-in pressure that is too low may cause the compressor to start too frequently, leading to excessive wear and tear on the equipment. On the other hand, a cut-in pressure that is too high may result in the compressor running for longer periods, consuming more energy and potentially causing damage to the system. Therefore, the correct answer is 552 kPa (80 psi) as it provides a balanced level of pressure for the compressor to start and operate effectively.

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About This Quiz
Do You Know How To Use Air Break? - Quiz

In the quiz below we, look and want to ascertain that you know how to use the air breaks. Despite of the answers you are going to give and the results, it is certain that you are going to learn.

2. When inspecting the air compressor drive belt, the driver must look for?

Explanation

The driver must inspect the air compressor drive belt for a loose belt, a cut belt, and a frayed belt. A loose belt can cause the air compressor to not function properly, while a cut belt can lead to complete failure of the compressor. A frayed belt indicates wear and tear, which can also affect the performance of the compressor. Therefore, the driver should look for all of these issues when inspecting the air compressor drive belt.

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3. When an air brake system is defective you must?

Explanation

When an air brake system is defective, it is unsafe to drive or operate the vehicle on any road or highway. This is because the air brake system is a critical component of a commercial vehicle's braking system, and a defect in this system can result in a loss of braking power. Driving with a defective air brake system poses a significant risk to the driver, passengers, and other road users. Therefore, it is essential to refrain from driving the vehicle until the air brake system is repaired and deemed safe for operation.

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4. When an air brake system is defective you must?

Explanation

When an air brake system is defective, it is unsafe to drive or operate the vehicle on any road or highway. This is because the air brake system is critical for the safe operation of the vehicle, especially in terms of stopping and slowing down. If the air brake system is defective, it can lead to a loss of braking power, making it difficult to control the vehicle and potentially causing accidents. Therefore, it is important to not drive or operate the vehicle until the air brake system is repaired or replaced.

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5. When an air brake brake system is defective you must?

Explanation

When an air brake brake system is defective, it is unsafe to drive or operate the vehicle on any road or highway. This is because the brakes are a critical component of a vehicle's safety system, and if they are not functioning properly, it can lead to accidents or loss of control. Therefore, it is necessary to refrain from driving the vehicle until the brake system is repaired or replaced.

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6. When inspecting the, the driver must look for?

Explanation

The driver must inspect the belt for any signs of damage or wear. A loose belt can lead to inefficient operation of the vehicle's systems. A cut belt can cause complete failure of the belt, resulting in loss of power to various components. A frayed belt indicates that it is worn out and may snap at any moment. Therefore, the driver should look for all of these issues to ensure the belt is in good condition and prevent any potential problems while driving.

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7. Drivers must be careful when conducting an inspection of the air brake system to avoid?

Explanation

When conducting an inspection of the air brake system, drivers must be careful to avoid unexpected vehicle movement, compressed air exhausting from components, and moving vehicle parts. This is because any of these scenarios can be potentially dangerous and can lead to accidents or injuries. Therefore, it is important for drivers to exercise caution and take necessary precautions while inspecting the air brake system to ensure their safety and the safety of others on the road.

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8. A reliable method for inspecting brake adjustment on a brake having an exposed push rod is?

Explanation

The most reliable method for inspecting brake adjustment on a brake with an exposed push rod is by measuring the applied push rod stroke. This involves measuring the distance that the push rod moves when the brakes are applied. By comparing this measurement to the manufacturer's specifications, one can determine if the brake adjustment is within the acceptable range. This method provides a direct and accurate assessment of the brake adjustment, making it a reliable choice for inspection.

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9. When a low air pressure warning device activates, the driver must?

Explanation

When a low air pressure warning device activates, it indicates that the air pressure in the braking system is below the safe level. This can lead to a loss of braking power, making it unsafe to continue driving. Therefore, the driver must come to a safe stop as soon as possible to avoid any potential accidents or further damage to the vehicle.

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10. When a vehicle's brakes do not comply with the Ontario Highway Traffic Act and regulations?

Explanation

When a vehicle's brakes do not comply with the Ontario Highway Traffic Act and regulations, both the vehicle operator and the driver may be charged. This means that both the person operating the vehicle and the person in control of the vehicle at the time of the offense can be held responsible for the non-compliant brakes. It is important for both the driver and the vehicle operator to ensure that the brakes meet the required standards to avoid any potential charges or penalties.

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11. When an air brake system is defective you must?

Explanation

When an air brake system is defective, it is unsafe to drive or operate the vehicle on any road or highway. Air brakes are an essential component for the safe operation of a vehicle, and if they are not functioning properly, it can lead to a loss of control and potentially cause accidents. Therefore, it is necessary to refrain from driving the vehicle until the air brake system is repaired or replaced.

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12. A reliable method for inspecting brake adjustment on a brake having an exposed push rod is?

Explanation

Measuring the applied push rod stroke is a reliable method for inspecting brake adjustment on a brake with an exposed push rod. This involves measuring the distance that the push rod moves when the brakes are applied. By comparing this measurement to the manufacturer's specifications, one can determine if the brake adjustment is within the recommended range. This method allows for a direct assessment of the brake's performance and can help identify any potential issues with the brake system.

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13. A vehicle's brakes must do more work when?

Explanation

When a vehicle goes faster, the brakes must do more work because the vehicle's momentum increases with speed. As the vehicle accelerates, it builds up more kinetic energy, which needs to be dissipated when the brakes are applied. This requires the brakes to exert more force to slow down or stop the vehicle effectively. Therefore, the correct answer is that the vehicle goes faster.

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14. The minimum and maximum pressure settings prescribed in the Ontario Highway Traffic Act and regulations are 552 kPa (80 psi) and 932 kPa (135 psi)?

Explanation

The given statement is true. According to the Ontario Highway Traffic Act and regulations, the minimum and maximum pressure settings prescribed are 552 kPa (80 psi) and 932 kPa (135 psi) respectively. This means that any pressure below 552 kPa or above 932 kPa would be considered outside the legal limits set by the regulations.

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15. A reliable method for inspecting brake adjustment on a brake having an exposed push rod is?

Explanation

To inspect brake adjustment on a brake with an exposed push rod, measuring the applied push rod stroke is a reliable method. By measuring the distance the push rod moves when the brakes are applied, one can determine if the brake adjustment is within the recommended range. This method allows for a quantitative assessment of the brake adjustment, providing a more accurate and objective evaluation compared to other options such as checking for a 90-degree angle or observing air pressure drop. Rolling the vehicle forward and applying the brakes may not provide an accurate assessment of the brake adjustment as it relies on subjective observations.

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16. When measuring the applied push rod stroke on brake having exposed push rods, air pressure must be between?

Explanation

The correct answer is 621 and 690 kPa (90 and 100 psi). This range of air pressure is required when measuring the applied push rod stroke on a brake with exposed push rods. It is important to have the correct air pressure to ensure accurate measurements and proper functioning of the brake system.

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17. A reliable method for inspecting brake adjustment on a brake having an exposed push rod is?

Explanation

Measuring the applied push rod stroke is a reliable method for inspecting brake adjustment on a brake with an exposed push rod. This involves measuring the distance the push rod moves when the brakes are applied. If the stroke is within the recommended range, it indicates that the brake adjustment is correct. However, if the stroke is too long or too short, it indicates that the brake adjustment needs to be adjusted. This method allows for a direct measurement of the push rod stroke, providing a reliable way to assess brake adjustment.

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18. When a driver finds a brake that is out of adjustment?

Explanation

If a driver finds a brake that is out of adjustment, the correct course of action is to not drive or operate the vehicle on any road or highway. This is because an improperly adjusted brake can affect the vehicle's ability to stop effectively, posing a safety risk to the driver, passengers, and other road users. It is important to address the issue before using the vehicle again to ensure safe operation.

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19. Air brake systems must comply with the Ontario Highway Traffic Act and regulations?

Explanation

Air brake systems must comply with the Ontario Highway Traffic Act and regulations at all times when being driven or operated on any road or highway. This means that the air brake systems on vehicles must meet the requirements set forth by the Act and regulations whenever they are in use on public roads. This ensures the safety and proper functioning of the air brake systems, which are essential for the safe operation of the vehicle. Compliance with these regulations is necessary to prevent accidents and maintain the overall safety of the roadways.

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20. Disc brake components include?

Explanation

The correct answer is Calipers and Rotors. Disc brakes consist of two main components: calipers and rotors. The calipers are responsible for squeezing the brake pads against the rotors, creating friction and slowing down the vehicle. The rotors, also known as brake discs, are attached to the wheel and provide a surface for the brake pads to grip onto. Together, the calipers and rotors work in tandem to provide effective braking power and control.

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21. The low air warning device must activate before air pressure drops to?

Explanation

The low air warning device is designed to activate before the air pressure drops to a dangerously low level. In this case, the correct answer is 380 kPa (55 psi), which is the lowest pressure among the given options. This means that the warning device should activate when the air pressure reaches this threshold, ensuring that the driver is alerted to the low air pressure before it drops even further.

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22. The air that exhausts from an air brake system can carry?

Explanation

The air that exhausts from an air brake system can carry dirt and dust, moisture, and oil. This is because the air in the system can pick up these substances as it circulates through the brake components. Dirt and dust can enter the system through various openings, moisture can condense in the system due to temperature changes, and oil can be present in the system due to leaks or lubrication. Therefore, the exhaust air from an air brake system can contain all of these substances.

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23. Air brake systems must comply with the Ontario Highway Traffic Act and regulations?

Explanation

Air brake systems must comply with the Ontario Highway Traffic Act and regulations at all times when being driven or operated on any road or highway. This means that the air brake systems must meet the requirements and standards set by the law and regulations, and they must be in proper working condition whenever the vehicle is being driven or operated on any road or highway. Compliance with these regulations ensures the safety of the vehicle and other road users.

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24. When an air brake system is defective you must?

Explanation

When an air brake system is defective, it is unsafe to drive or operate the vehicle on any road or highway. Defective air brakes can lead to a loss of braking power, making it difficult to stop the vehicle safely. Continuing to drive in such conditions can pose a significant risk to the driver, passengers, and other road users. It is crucial to address the issue promptly by seeking professional help or having the vehicle towed to a service station for repairs.

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25. When measuring the applied push rod stroke on brakes having push rods, air pressure must be between?

Explanation

The correct answer is 621 and 690 kPa (90 and 100 psi). This range of air pressure is necessary when measuring the applied push rod stroke on brakes with push rods. It ensures that the measurement is accurate and within the appropriate range for the brake system. Air pressure that is too high or too low could result in inaccurate measurements or potential damage to the brake system.

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26. Anti-lock braking systems (ABS) use warning indicator lights to indicate?

Explanation

Anti-lock braking systems (ABS) use warning indicator lights to indicate malfunctions of the system. These indicator lights are designed to alert the driver when there is a problem with the ABS, such as a sensor failure or a malfunction in the hydraulic system. By illuminating the warning light, the ABS system is able to communicate to the driver that there is an issue that needs to be addressed. This allows the driver to take appropriate action, such as seeking repairs or maintenance, to ensure the ABS is functioning properly and their vehicle is safe to drive.

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27. When a vehicle's brakes do not comply with the Ontario Highway Traffic Act and regulations?

Explanation

When a vehicle's brakes do not comply with the Ontario Highway Traffic Act and regulations, both the vehicle operator and the driver may be charged. This means that both the person operating the vehicle and the person driving the vehicle can be held responsible for the non-compliance of the brakes. The responsibility is shared between these two individuals, and they may face charges accordingly.

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28. When conducting an inspection of the air brake system, the vehicle should be parked securely on a?

Explanation

When conducting an inspection of the air brake system, it is important to park the vehicle securely on a level surface and in a safe location. This ensures that the vehicle is stable and not at risk of rolling or causing any accidents during the inspection. Parking on a level surface allows for accurate assessment of the air brake system, as any abnormalities or issues can be easily detected. Additionally, parking in a safe location ensures the safety of the inspector and other individuals nearby, minimizing any potential hazards that may arise during the inspection process.

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29. A governor controls air compressor?

Explanation

Cut-in and cut-out pressures refer to the pressure levels at which an air compressor starts and stops operating. The governor is responsible for controlling these pressure levels. When the pressure drops below the cut-in pressure, the governor activates the compressor to start, and when the pressure reaches the cut-out pressure, the governor stops the compressor. Therefore, the governor plays a crucial role in controlling the operation of the air compressor based on the cut-in and cut-out pressures.

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30. Repair and re-adjustment of all types air brakes may be performed by?

Explanation

Certified technicians are qualified and trained professionals who have the necessary knowledge and skills to repair and re-adjust all types of air brakes. They have undergone specific training and have obtained certification to ensure they can perform these tasks safely and effectively. Licensed drivers and drivers with a valid air brake endorsement may have some knowledge about air brakes, but they may not have the expertise or training required to perform complex repairs and re-adjustments. Therefore, certified technicians are the most suitable individuals to carry out these tasks.

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31. When inspecting visible air brake hoes and tubes, the driver must check for:

Explanation

The driver must check for all of the above when inspecting visible air brake hoses and tubes. This includes checking for any audible air leaks, looking for any damaged or worn air lines, and ensuring that there are no improper fittings used to connect or repair an air line. It is important to check for all of these issues to ensure that the air brake system is functioning properly and safely.

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32. A brake having an exposed push rod is out of adjustment when?

Explanation

When the push rod stroke exceeds the adjustment limit of the brake chamber, it means that the push rod has extended too far and is not properly adjusted. This can lead to ineffective braking and potentially cause safety issues. It is important to ensure that the push rod is adjusted within the specified limits to maintain proper brake function.

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33. The air loss rate on a single vehicle ( bus, tractor or truck ) must not exceed?

Explanation

The air loss rate on a single vehicle (bus, tractor, or truck) must not exceed 21 kPa (3 psi) per minute. This means that the vehicle should not lose more than 21 kPa or 3 psi of air pressure in its system within a minute. This requirement is important for maintaining the proper functioning of the vehicle's braking system, as the air pressure is crucial for effective braking. Exceeding this limit could lead to compromised braking performance and potential safety hazards.

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34. When inspecting the air tanks, the driver must look for?

Explanation

The driver must inspect the air tanks for any signs of insecure mounting. This means checking if the air tanks are properly secured and not loose or unstable. This is important to ensure the safety and stability of the vehicle's air system. A loose or insecurely mounted air tank can lead to air leaks or other malfunctions, which can affect the braking system and overall vehicle performance. Therefore, it is crucial for the driver to look for this issue during the inspection.

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35. An air tank drain valve that fails to function?

Explanation

The correct answer is "Is a defect of the air brake system." If an air tank drain valve fails to function, it indicates a defect in the air brake system. The drain valve is an essential component that helps remove moisture and contaminants from the air tanks. If it fails to function, it can lead to a buildup of moisture and contaminants, which can affect the performance and efficiency of the air brake system. Therefore, it is important to address this issue and fix the defect in order to maintain the proper functioning of the air brake system.

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36. A tractor protection valve is defective if the trailer supply valve is closed ( pulled out ) and air exhausts from the?

Explanation

If the tractor protection valve is defective, it means that it is not functioning properly. In this case, when the trailer supply valve is closed (pulled out), air will exhaust from the trailer service line when the brake pedal is pressed. This indicates a problem with the valve as it should not be allowing air to escape from the service line in this situation.

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37. Air compressor cut-in pressure must never be less than?

Explanation

The cut-in pressure of an air compressor refers to the minimum pressure at which the compressor starts running to build up pressure. It is important for the cut-in pressure to be set at an appropriate level to ensure the efficient operation of the compressor. In this case, the correct answer is 552 kPa (80 psi). This means that the compressor should start running when the pressure drops to 552 kPa or below. Setting the cut-in pressure too low could result in the compressor constantly starting and stopping, leading to inefficiency and unnecessary wear and tear on the equipment.

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38. The air loss rate on a towing vehicle with two or more trailers must not exceed?

Explanation

The correct answer is 41 kPa (6 psi) per minute. This is the maximum allowable air loss rate for a towing vehicle with two or more trailers. It is important to maintain proper air pressure in the braking system to ensure safe and effective braking. If the air loss rate exceeds this limit, it could indicate a problem with the braking system that needs to be addressed.

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39. The air loss rate on a single vehicle (Bus, Tractor or Truck) must not exceed?

Explanation

The air loss rate on a single vehicle (Bus, Tractor or Truck) must not exceed 21 kPa (3 psi) per minute. This means that the vehicle should not lose more than 21 kPa (3 psi) of air pressure in the air system in one minute. This is important because maintaining proper air pressure is crucial for the safe operation of the vehicle's braking system. If the air loss rate exceeds this limit, it could lead to brake failure and compromise the safety of the vehicle.

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40. A vehicle should only be driven when air pressure is in the normal operating range. A drop in air pressure below the cut-in setting is a sign that the air brake system is malfunctioning?

Explanation

If a vehicle's air pressure drops below the cut-in setting, it indicates a malfunction in the air brake system. This is because the cut-in setting is the minimum air pressure required for the system to operate effectively. Therefore, it is important to only drive a vehicle when the air pressure is within the normal operating range to ensure the proper functioning of the air brake system.

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41. Disc brake components include?

Explanation

The correct answer is Calipers and Rotors. Calipers are responsible for applying pressure to the brake pads, which in turn press against the rotors to create friction and slow down the vehicle. Rotors, also known as brake discs, are attached to the wheels and provide a surface for the brake pads to grip onto. Together, the calipers and rotors form the key components of a disc brake system, allowing for effective braking and control of the vehicle.

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42. Hydraulic systems use brake?

Explanation

Hydraulic systems use brake fluid because it has the necessary properties to function effectively in the system. Brake fluid is a type of hydraulic fluid that is specifically designed to withstand high temperatures and pressures. It has a high boiling point, low compressibility, and excellent lubrication properties. These characteristics make it ideal for transmitting force and energy within the hydraulic system, allowing the brakes to operate efficiently and effectively.

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43. The air loss rate on a towing vehicle with two or more trailers must not exceed?

Explanation

The correct answer is 41 kPa (6 psi) per minute. When towing a vehicle with two or more trailers, it is important to ensure that the air loss rate does not exceed this limit. This is crucial for maintaining proper braking and stability while on the road. If the air loss rate exceeds this limit, it could lead to a loss of control and potentially dangerous situations. Therefore, it is essential to regularly check and maintain the air pressure in the towing vehicle's braking system to ensure it stays within the recommended limits.

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44. A tractor protection valve is defective if the trailer supply valve is closed ( pulled out ) and air exhausts from the?

Explanation

If the tractor protection valve is defective, it means that it is not functioning properly. In this scenario, when the trailer supply valve is closed (pulled out), air should not be able to exhaust from the trailer service line with the brake pedal pressed. However, if the tractor protection valve is defective, air will still exhaust from the trailer service line even when the brake pedal is pressed. Therefore, the correct answer is "Trailer service line with the brake pedal pressed."

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45. When air loss from an air brake system exceeds the prescribed limits?

Explanation

When air loss from an air brake system exceeds the prescribed limits, it is not safe to drive the vehicle on any road or highway. This is because the air brake system is essential for the safe operation of the vehicle, and if there is excessive air loss, the brakes may not function properly, putting the driver, passengers, and other road users at risk. Therefore, it is necessary to address the issue and have the vehicle repaired before it can be driven again.

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46. When inspecting visible air brake hoses and tubes, the driver check for?

Explanation

When inspecting visible air brake hoses and tubes, the driver checks for audile air leaks, damaged or worn air lines, and improper fittings used to connect or repair an air line. This is because all of these issues can affect the proper functioning of the air brake system and compromise the safety of the vehicle. Therefore, the driver should inspect for all of these potential problems during the inspection process.

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47. Repair and re-adjustment of all types of air brakes may be performed by?

Explanation

The repair and re-adjustment of all types of air brakes should be performed by a certified technician. This ensures that the individual has the necessary knowledge and expertise to safely and effectively handle the complex systems involved in air brakes. Licensed drivers and drivers with a valid air brake endorsement may have some understanding of air brakes, but they may not have the comprehensive training and skills required to perform repairs and adjustments. Certified technicians have undergone specific training and have the necessary certifications to handle these tasks.

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48. The brake systems on  most large commerical vehicles use?

Explanation

Most large commercial vehicles use compressed air to apply the brakes. This is known as an air brake system. In this system, air is stored in a tank and when the brake pedal is pressed, the air is released to activate the brake mechanism. Compressed air is used because it can provide a consistent and reliable force to apply the brakes, especially for heavy vehicles that require a higher braking force. Steam and water are not commonly used in brake systems, and while brake fluid is used in some vehicles, it is not the primary choice for large commercial vehicles.

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49. The low air warning device must activate before air pressure drops to?

Explanation

The low air warning device must activate before air pressure drops to 380 kPa (55 psi) because this is the minimum safe level of air pressure required for the braking system to function properly. If the air pressure drops below this level, it could indicate a leak or malfunction in the system, which would require immediate attention to prevent brake failure. Therefore, activating the warning device at this pressure ensures that drivers are alerted in time to address any potential issues and maintain the safety of the vehicle.

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50. Driving a vehicle with an air brake system that is outside the normal operating pressure range is?

Explanation

Driving a vehicle with an air brake system that is outside the normal operating pressure range is not safe at any time. The air brake system is designed to work within a specific pressure range to ensure proper braking performance. If the pressure is too low, the brakes may not engage properly, resulting in longer stopping distances and increased risk of accidents. On the other hand, if the pressure is too high, it can cause the brakes to lock up, leading to loss of control of the vehicle. Therefore, it is crucial to maintain the air brake system within the recommended pressure range for safe driving.

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51. To prevent vehicle movement during an inspection of the air brake system, a driver should use?

Explanation

To prevent vehicle movement during an inspection of the air brake system, a driver should use wheel chocks or blocks. Wheel chocks or blocks are devices placed against the wheels of a vehicle to prevent it from rolling or moving. They provide an additional level of safety by immobilizing the vehicle, ensuring that it remains stationary while the inspection is being carried out. This helps to prevent accidents or injuries that could occur if the vehicle were to unexpectedly move during the inspection process.

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52. Brake fade can result from?

Explanation

Brake fade occurs when the brakes become overheated, causing a decrease in braking effectiveness. High brake temperatures can lead to this condition, as the excessive heat can cause the brake pads and rotors to lose their frictional properties. This can occur during prolonged or heavy braking, such as when driving downhill or towing heavy loads. The heat generated during braking can also cause brake fluid to boil, further reducing braking performance. Therefore, high brake temperatures are a common cause of brake fade.

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53. When trailer couplers or gladhands are cross-connected?

Explanation

When trailer couplers or gladhands are cross-connected, the correct answer is that the trailer service and spring brakes will not function correctly. Cross-connecting the couplers or gladhands can lead to a loss of air pressure in the brake system, causing the brakes to fail. This can be extremely dangerous as it can result in a loss of control over the trailer and increase the risk of accidents. It is important to ensure that the couplers and gladhands are properly connected to prevent any issues with the brake system.

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54. When inspecting ,  the driver must look for?

Explanation

When inspecting, the driver must look for broken or cracked brake drums or rotors. This is important because any damage to the brake drums or rotors can affect the braking performance of the vehicle. Cracks or breaks in these components can lead to reduced braking power or even complete brake failure, posing a serious safety risk. Therefore, it is crucial for the driver to identify and address any issues with the brake drums or rotors during inspection to ensure the proper functioning of the braking system.

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55. High brakes temperature can result from?

Explanation

High brake temperature can result from repeated brake use driving down along or steep hills, as the constant friction between the brake pads and rotors generates heat. Similarly, repeated brake use in stop and go traffic can also cause high brake temperature due to frequent braking and limited time for the brakes to cool down. Additionally, severe braking, such as sudden and hard stops, can rapidly increase the brake temperature. Therefore, all of the mentioned scenarios can contribute to high brake temperature.

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56. Drivers must be careful  when conducting  an inspection of the air brake system to avoid?

Explanation

When conducting an inspection of the air brake system, drivers must be careful to avoid unexpected vehicle movement, compressed air exhausting from components, and moving vehicle parts. This means that they need to ensure that the vehicle is properly secured and that all components are functioning correctly. They should also be cautious of any potential hazards such as leaking air or loose parts that could cause injury or damage. Being mindful of these risks is crucial to maintaining safety while inspecting the air brake system.

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57. Using anti-lock braking systems (ABS) to prevent the wheels from locking?

Explanation

Using anti-lock braking systems (ABS) helps maintain steering control during emergency braking. ABS prevents the wheels from locking up, allowing the driver to maintain control and steer the vehicle while braking hard. This is especially important in emergency situations where sudden braking is required to avoid a collision. Without ABS, locked wheels can cause the vehicle to skid and lose steering control, increasing the risk of an accident. ABS technology helps to prevent this by modulating the braking pressure on each wheel, ensuring that the wheels continue to rotate and maintain traction with the road surface.

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58. When inspecting the , the driver must look for?

Explanation

When inspecting the brake system, the driver must look for air leaks, cracks, and non-manufactured holes. This is important because any of these issues can lead to a loss of brake pressure or compromised braking ability, which can be extremely dangerous. Air leaks can cause the brake system to become less efficient, while cracks and non-manufactured holes can weaken the structure of the brake components. Therefore, it is crucial for the driver to thoroughly inspect the brake system for these potential problems to ensure safe operation of the vehicle.

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59. The vehicle fails the test when the cut-out pressure setting is higher than 932 kPa (135 psi) or lower than 690 kPa (100 psi), or cut-in pressure setting is lower than 552 kPa (80 psi)?

Explanation

The statement is true because if the cut-out pressure setting of the vehicle is higher than 932 kPa or lower than 690 kPa, or if the cut-in pressure setting is lower than 552 kPa, then the vehicle will fail the test.

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60. When inspecting the foundation brake components, the driver must look for

Explanation

When inspecting the foundation brake components, the driver must look for brake lining that is not against the drum when brakes are applied. This is important because if the brake lining is not making proper contact with the drum, it will not be able to effectively stop the vehicle. The driver must also look for brake lining that is too thin or cracked, as this can indicate that the brake lining is worn out and needs to be replaced. Additionally, the driver should check for grease or oil on the brake lining, as this can reduce the friction between the brake lining and the drum, resulting in reduced braking performance. Therefore, all of the above options are important factors to consider when inspecting foundation brake components.

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61. When air brake system pressure drops below 414 kPa (60 psi), the spring brakes?

Explanation

When the air brake system pressure drops below 414 kPa (60 psi), the spring brakes will automatically apply. This is because the spring brakes are designed to engage and apply the brakes when there is a loss of air pressure in the system. This is a safety feature that ensures the vehicle comes to a stop in case of a failure or loss of air pressure in the brake system.

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62. A spring brake control valve is normally?

Explanation

A spring brake control valve is a push/pull type valve located near the driver. This type of valve is commonly used in commercial vehicles to control the spring brakes. By pulling the valve, the spring brakes are released, allowing the vehicle to move. On the other hand, pushing the valve applies the service brake, causing the vehicle to stop. The location of this valve near the driver ensures easy access and control over the spring brakes, enhancing safety and convenience.

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63. When , air pressure must be between?

Explanation

Diagram 11-1: Air pressure above 621 kPa (90 psi) with spring brakes released

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64. The part inside a spring brake chamber that can be hazardous is the?

Explanation

The large coil spring in a spring brake chamber can be hazardous because it is under a significant amount of tension. If the spring were to suddenly release or break, it could cause the brake chamber to malfunction, leading to a loss of braking power. This could result in a dangerous situation, especially when driving heavy vehicles or on steep slopes. Therefore, it is important to handle and maintain the large coil spring with caution to prevent any accidents or injuries.

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65. A properly functioning air brake system?

Explanation

A properly functioning air brake system should not have any noticeable air leaks. Air leaks can lead to a decrease in brake efficiency and can compromise the overall performance of the system. Therefore, it is important for an air brake system to be free from any leaks to ensure safe and effective braking.

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66. A tractor protection valve is defective if the trailer supply valve is closed ( pulled out ) and air exhausts from the?

Explanation

In a tractor-trailer system, the tractor protection valve is responsible for preventing loss of air pressure in the trailer's air supply system. When the trailer supply valve is closed (pulled out), the tractor protection valve should prevent air from exhausting from the trailer service line when the brake pedal is pressed. If air is still exhausting from the trailer service line with the brake pedal pressed, it indicates a defect in the tractor protection valve, as it is not properly preventing air loss.

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67. The compressed air in an air brake system is stored in?

Explanation

In an air brake system, the compressed air is stored in the vehicle's air tanks. These tanks act as reservoirs to store the compressed air that is generated by the air compressor. The compressed air is then used to apply the brakes when the driver activates the brake pedal. The air tanks ensure that there is a sufficient supply of compressed air available for the brake system to function effectively.

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68. Brakes convert the energy of a moving vehicle into?

Explanation

When a vehicle is in motion, it possesses kinetic energy. Brakes are designed to convert this kinetic energy into heat energy through friction. As the brakes are applied, the brake pads press against the rotors, creating resistance and converting the vehicle's energy into heat. This heat is then dissipated into the surrounding air. Therefore, the correct answer is heat.

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69. When inspecting the brake chambers on each side of a steering axle, the driver must ensure that slack adjusters are?

Explanation

When inspecting the brake chambers on each side of a steering axle, the driver must ensure that the slack adjusters are the same effective length and the brake chambers are the same size. This is important for maintaining proper brake balance and ensuring that both sides of the axle are working together effectively. If the slack adjusters are not the same length, it could lead to uneven braking and potential steering issues. Similarly, if the brake chambers are not the same size, it could result in uneven braking force and affect the overall performance of the braking system.

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70. When brake chamber push rod stoke exceeds the adjustment limit?

Explanation

When the brake chamber push rod stroke exceeds the adjustment limit, it means that the brakes are not properly adjusted. This can result in reduced braking ability because the brakes may not engage fully or evenly. As a result, the vehicle may take longer to stop or may not be able to stop effectively, leading to a decrease in braking ability.

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71. Air tanks must be drained regularly because?

Explanation

Air tanks must be drained regularly because moisture and oil collect in them. Moisture and oil can accumulate in the air tanks due to condensation and oil carryover from the compressor. If not drained regularly, this can lead to corrosion and damage to the tank, as well as affect the performance of the air system. Draining the tanks helps to remove the accumulated moisture and oil, ensuring the proper functioning and longevity of the air tanks.

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72. To check the air pressure in a vehicle's air brake system, a driver?

Explanation

To check the air pressure in a vehicle's air brake system, a driver reads the gauges on the instrument panel. This is because the air pressure gauges on the instrument panel display the current air pressure in the air brake system. By monitoring these gauges, the driver can ensure that the air pressure is within the appropriate range for safe braking. This allows the driver to take necessary actions, such as adding air or releasing air, to maintain the proper air pressure in the system.

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73. Air compressors are powered directly by the engine or by using?

Explanation

Air compressors are powered by belts and pulleys. Belts and pulleys are commonly used to transfer power from the engine to the air compressor. The engine drives the belt, which in turn rotates the pulley attached to the air compressor. This rotational motion of the pulley is converted into compressed air by the air compressor. Belts and pulleys provide a reliable and efficient method of transferring power, making them a popular choice for powering air compressors.

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74. To test the low air warning device, the ignition switch must be turned on and air pressure must be?

Explanation

To test the low air warning device, the air pressure needs to be reduced from the normal operating range until the device activates. This is because the low air warning device is designed to alert the driver when the air pressure in the braking system falls below a certain level. By reducing the air pressure from the normal operating range, it simulates a situation where there is a potential problem with the braking system, and if the device activates, it indicates that the warning system is functioning correctly.

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75. A reliable method for inspecting brake adjustment on a brake having  an exposed push rod is?

Explanation

To inspect brake adjustment on a brake with an exposed push rod, measuring the applied push rod stroke is a reliable method. This involves measuring the distance that the push rod moves when the brakes are applied. By comparing this measurement to the manufacturer's specifications, one can determine if the brake adjustment is within the acceptable range. This method allows for a direct assessment of the brake's performance and ensures that the push rod is functioning correctly.

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76. The low air warning device must activate before air pressure drops to?

Explanation

The low air warning device is a safety feature in vehicles that alerts the driver when the air pressure in the braking system drops to a dangerously low level. This is important because if the air pressure drops too low, the brakes may not function properly, leading to a potential loss of control of the vehicle. The correct answer is 380 kPa (55 psi) because this is the minimum air pressure at which the warning device should activate, ensuring that the driver is alerted before the pressure drops to a critical level.

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77. Vehicles with air brakes must have air pressure gauges that indicate the pressure in the?

Explanation

Vehicles with air brakes must have air pressure gauges that indicate the pressure in the primary and secondary air tanks. This is important because the air tanks store compressed air that is used to operate the brakes. Monitoring the air pressure in these tanks is crucial for ensuring that there is enough pressure to effectively engage the brakes when needed. The gauges allow the driver to easily check the air pressure levels and take appropriate action if there is a problem or if the pressure is getting too low.

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78. Trailer couplers or 'gladhands' are usually?

Explanation

Trailer couplers or 'gladhands' are color matched and designed to prevent cross-connection. This means that the couplers on the trailer and the vehicle will have matching colors, typically yellow and black, to ensure that they are connected correctly. The color matching helps to prevent any potential cross-connection between the air lines of different trailers, which could cause issues with the braking system. By using color matching and designing the couplers to prevent cross-connection, it ensures that the trailers can be safely and securely connected to the vehicle.

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79. A vehicle's brakes must do more work when?

Explanation

When a vehicle carries more weight, the brakes have to work harder to slow down or stop the vehicle. This is because the additional weight increases the momentum and inertia of the vehicle, requiring more force from the brakes to overcome it. Similarly, when a vehicle carries less weight or goes slower, the brakes do not have to work as hard because there is less momentum and inertia to overcome. Therefore, the correct answer is that the vehicle carries more weight.

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80. The vehicle passes the test when the cut-out pressure setting is between 690 and 932 kPa (100 and 135 psi) and the cut-in pressure setting is 552 kPa (80 psi) or higher?

Explanation

The statement is true because it states that the vehicle passes the test when the cut-out pressure setting is between 690 and 932 kPa (100 and 135 psi) and the cut-in pressure setting is 552 kPa (80 psi) or higher. Therefore, if the cut-out pressure is within the specified range and the cut-in pressure is equal to or greater than 552 kPa (80 psi), the vehicle will pass the test.

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81. Alcohol evaporators may be used to?

Explanation

Alcohol evaporators help prevent moisture in the air brake system from freezing. Moisture can accumulate in the air brake system, and in cold temperatures, it can freeze and cause issues with the brakes. Alcohol evaporators are used to introduce alcohol into the system, which lowers the freezing point of the moisture, preventing it from freezing and causing malfunctions.

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82. When inspecting the air tanks, the driver must look for?

Explanation

The driver must inspect the air tanks for an insecurely mounted air tank. This means that the air tank is not securely attached or fixed in place. It could be loose or not properly fastened, which can pose a safety risk. It is important for the driver to ensure that all components of the air tanks are securely mounted to prevent any potential accidents or malfunctions while driving.

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83. If a vehicle moves while the spring brakes are applied, the vehicle has?

Explanation

If a vehicle moves while the spring brakes are applied, it indicates that the spring brakes are defective. Spring brakes are designed to automatically engage when the air pressure in the brake system drops below a certain level. This ensures that the vehicle remains stationary when parked. If the vehicle is able to move with the spring brakes applied, it suggests that the spring brakes are not functioning properly and may require repair or replacement.

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84. The air loss rate on a single vehicle (bus, tractor or truck) must not exceed?

Explanation

The air loss rate on a single vehicle must not exceed 21 kPa (3 psi) per minute. This is important because excessive air loss can lead to a decrease in braking efficiency, which can be extremely dangerous on the road. It is crucial for vehicles to maintain a stable air pressure system to ensure optimal braking performance and overall safety.

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85.  Side view and underside view of a conventional 18-wheeler semi-trailer truck with an enclosed cargo space. The underside view shows the arrangement of the 18 tires (wheels). Shown in blue in the underside view are the axles, drive shaft, and differentials. The legend for labeled parts of the truck is as follows: 1. tractor unit 2. semi-trailer (detachable) 3. engine compartment 4. cabin 5. sleeper (not present in all trucks) 6. air dam 7. fuel tanks 8. fifth wheel coupling 9. enclosed cargo space 10. landing gear - legs for when semi-trailer is detached 11. tandem axles
 

Explanation

The answer lists the labeled parts of the truck in the correct order as mentioned in the description. It includes the tractor unit, semi-trailer (detachable), engine compartment, cabin, sleeper (not present in all trucks), air dam, fuel tanks, fifth wheel coupling, enclosed cargo space, landing gear, and tandem axles.

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86. To test air pressure build-up time, the engine must be running at?

Explanation

To test air pressure build-up time, the engine must be running at 600 to 900 rpm. This range of engine speed allows for an optimal balance between air intake and pressure build-up. Running the engine at a lower speed may not provide enough air intake to accurately measure the pressure build-up, while running it at a higher speed may result in excessive air intake and potentially inaccurate readings. Therefore, the recommended rpm range ensures the most reliable and consistent results for testing air pressure build-up time.

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87. A brake having an exposed push rod is out of adjustment when?

Explanation

The correct answer is that the push rod stroke exceeds the adjustment limit of the brake chamber. This means that the push rod is extending too far when the brakes are applied, indicating that the brake is not properly adjusted. When the push rod stroke exceeds the adjustment limit, it can cause reduced braking effectiveness and potentially lead to brake failure. It is important to regularly check and adjust the brake chamber to ensure proper brake operation and safety.

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88. A trailer supply valve is usually?

Explanation

The correct answer is a push/pull type valve located near the driver that supplies air to the trailer. This valve is typically operated by pulling it to release the spring brakes and pushing it to apply the service brakes. It is not located in the same position on all commercial vehicles, and it is not a toggle-type valve.

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89. The brake pedal in an air brake system is used to?

Explanation

The brake pedal in an air brake system is used to apply the vehicle service brakes. When the driver presses the brake pedal, it activates the brake system, causing the brake pads to squeeze against the brake rotors or drums, creating friction and slowing down or stopping the vehicle. This allows the driver to have control over the vehicle's speed and bring it to a halt when needed.

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90. Wedge brake components include?

Explanation

Wedge brake components include brake drums and brake shoes. Brake drums are the round metal discs that are attached to the wheel hub and rotate with the wheel. Brake shoes are curved metal plates that are lined with friction material and are pressed against the inside surface of the brake drum to create friction and slow down or stop the vehicle. These components work together to convert the kinetic energy of the moving vehicle into heat energy through friction, thus allowing the vehicle to come to a halt.

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91. Trailer couplers or gladhands are used to connect the?

Explanation

Trailer couplers or gladhands are used to connect the towing vehicle air brake system to the trailer air brake system. This connection allows the towing vehicle to control the brakes on the trailer, ensuring synchronized braking and safe operation while towing.

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92. When air brakes are applied or released, the brakes will respond?

Explanation

When air brakes are applied or released, there is a split-second delay before the brakes respond. This delay is due to the time it takes for the air pressure to build up or release within the brake system. Once the pressure reaches the desired level, the brakes will then respond and engage or disengage accordingly. This delay ensures that the brakes are activated or released smoothly and efficiently, providing the necessary control and safety while operating the vehicle.

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93. When a vehicle's brakes are out of adjustment?

Explanation

When a vehicle's brakes are out of adjustment, the spring brakes may not stop or hold a vehicle. This means that the spring brakes, which are designed to engage when the regular brakes fail, may not function properly. As a result, the vehicle may not be able to come to a complete stop or be held in place when the brakes are applied. This can pose a significant safety risk, as the driver may have difficulty controlling the vehicle and stopping it in emergency situations. It is important to regularly check and adjust the brakes to ensure their proper functioning.

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94. The brake pedal in an air brake system is used to?

Explanation

The brake pedal in an air brake system is used to apply the vehicle service brakes. When the driver presses the brake pedal, it activates the air brake system, causing air pressure to be released from the brake chambers. This pressure then applies the brake shoes or pads to the brake drums or rotors, creating friction and slowing down the vehicle. Therefore, the brake pedal is responsible for applying the brakes and bringing the vehicle to a stop.

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95. Air compressors?

Explanation

Air compressors are devices that are used to compress air and store it in a smaller space. They do not contain brake fluid or generate heat to stop a vehicle. Therefore, the correct answer is "Force air into a smaller space."

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96. When measuring the applied push rod stroke on brakes having exposed push rods, air pressure must be between?

Explanation

Diagram 11-2: Air pressure between 621 and 690 kPa (90 and 100 psi) with the service brake fully applied

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97. Safety valves prevent?

Explanation

Safety valves are designed to prevent overpressure in the air brake system. When the pressure in the system exceeds a certain limit, the safety valve opens, allowing the excess pressure to escape and preventing any damage or failure that could occur due to excessive pressure. This helps to maintain the proper functioning of the air brake system and ensures the safety of the vehicle and its occupants.

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98. An air tank drain valve that fails to function?

Explanation

The given correct answer states that a drain valve that fails to function is a defect of the air brake system. This means that if the drain valve, which is responsible for removing moisture and contaminants from the air tank, is not working properly, it signifies a problem in the air brake system. A malfunctioning drain valve can lead to the accumulation of moisture and contaminants in the air tank, which can affect the performance and efficiency of the air brake system. Therefore, it is important to ensure that the drain valve is functioning correctly to maintain the proper operation of the air brake system.

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99. The points where the air compressor is turned on and off determine the normal operating pressure range of an air brake system. Cut-Out and Cut-In pressure is normally?

Explanation

Below the Cut-Out setting and must never be less than 552 kPa (80 psi)

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100. The normal range of air pressure in an air brake system is between

Explanation

The normal range of air pressure in an air brake system is between 552 932 kPa and 80 135 psi. This range is considered to be the optimal operating pressure for the air brake system to function effectively. If the pressure falls below or exceeds this range, it can lead to brake malfunctions or failures. Therefore, it is crucial to maintain the air pressure within this specified range to ensure safe and efficient braking in vehicles equipped with air brakes.

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101. A vehicle's brakes must do more work when?

Explanation

When a vehicle goes faster, the brakes must do more work to slow down or stop the vehicle due to the increased momentum and kinetic energy. As the speed increases, it takes more force and distance for the brakes to bring the vehicle to a halt. Therefore, the correct answer is "The vehicle goes faster."

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102. The normal range of air pressure in an air brake system is between

Explanation

The normal range of air pressure in an air brake system is between 552,932 kPa and 80,135 psi. This range is considered to be the standard operating pressure for air brakes, ensuring optimal performance and safety. Air pressure within this range allows for proper braking and efficient transmission of force from the brake pedal to the brake pads or shoes. Deviating from this range can result in decreased braking effectiveness or potential damage to the system.

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103. The points where the air compressor is turned on and off determine the normal operating pressure range of an air brake system. Cut-Out and Cut-In pressure is normally?

Explanation

Below the Cut-Out setting and must never be less than 552 kPa (80 psi)

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104. The type of air brake components on most large commerical vehicles are either?

Explanation

Most large commercial vehicles are equipped with either drum or disc brakes as their air brake components. Drum brakes are commonly used in heavy-duty vehicles due to their ability to handle high heat and heavy loads. They consist of a rotating drum and brake shoes that press against the drum to create friction and slow down the vehicle. Disc brakes, on the other hand, use a caliper and brake pads to squeeze a rotating disc, generating friction and stopping the vehicle. Both types of brakes are effective in commercial vehicles and are chosen based on factors such as vehicle weight, braking performance, and cost.

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105. The ability of the brakes to stop a vehicle

Explanation

When a vehicle is overloaded, the weight of the vehicle increases beyond its capacity. This can lead to a loss of braking ability because the brakes may not be able to effectively stop the vehicle due to the excessive weight. Therefore, the statement "May be lost when a vehicle is overloaded" is a correct explanation for the given answer.

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106. The air brake system on a trailer includes?

Explanation

The air brake system on a trailer includes air tanks and automatic spring brake application. Air tanks store compressed air that is used to activate the brakes. The automatic spring brake application feature ensures that the brakes are applied automatically in case of a loss of air pressure or disconnection between the trailer and the tractor. This helps to ensure the safety of the vehicle by preventing it from rolling or moving unintentionally.

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107. The points where the air compressor is turned on and off determine the normal operating pressure range of an air brake system. Cut-Out and Cut-In pressure is normally?

Explanation

Below the Cut-Out setting and must never be less than 552 kPa (80 psi)

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108. The normal operating pressure range for air brake systems is?

Explanation

The correct answer is 552 to 932 kPa (80 to 135 psi). This range is the normal operating pressure for air brake systems. It is important for the air pressure in the system to be within this range to ensure proper functioning of the brakes. If the pressure is too low, the brakes may not engage properly, and if the pressure is too high, it may cause damage to the system. Therefore, maintaining the air pressure within this range is crucial for the safe operation of air brake systems.

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109. are?

Explanation

This feature is used to decrease the amount of force applied to the service brakes on the front steering axle. This can help prevent the front wheels from locking up or skidding during braking, which could result in a loss of steering control. By reducing the brake force on the front steering axle, the vehicle is able to maintain better stability and maneuverability while braking.

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110. Air brake chamber push rod stroke is the result of?

Explanation

The push rod stroke in an air brake chamber is the result of compressed air entering the brake chamber. When the brake pedal is pressed, it activates the air brake system, causing compressed air to enter the brake chamber. This compressed air pushes against the push rod, which in turn applies force to the brake shoes or pads, resulting in the braking action. Therefore, the push rod stroke is directly influenced by the presence of compressed air in the brake chamber.

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111. Wedge brake components include?

Explanation

Wedge brake components include brake drums and brake shoes. Brake drums are cylindrical-shaped components that rotate with the wheel and provide a surface for the brake shoes to press against. Brake shoes are curved metal plates with friction material on the outer surface. When the brake pedal is pressed, the brake shoes are pushed against the brake drums, creating friction and slowing down or stopping the vehicle.

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112. When a spring brake chamber has been disabled by a 'caging bolt' or other mechanism?

Explanation

When a spring brake chamber has been disabled by a 'caging bolt' or other mechanism, the spring brake will not apply. This means that the spring brake will not engage or activate when the brakes are applied. This can be dangerous as the vehicle may not be able to come to a complete stop or may experience difficulty in braking effectively. It is important for drivers to be aware of this and ensure that the spring brake is functioning properly to maintain safety on the road.

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113. An air dryer removes moisture, which is excelled when the?

Explanation

When the compressor reaches cut-out pressure, it means that it has reached the maximum pressure level and is no longer compressing air. At this point, the air dryer is able to remove moisture from the compressed air. As the air passes through the air dryer, any moisture present in the air is removed, ensuring that the air supplied to the system is dry. Therefore, the correct answer is that the air dryer removes moisture when the compressor reaches cut-out pressure.

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114. Spring brake chambers?

Explanation

Spring brake chambers are larger than service brake chambers because they are designed to provide the necessary force to engage the parking brake and hold the vehicle in place when it is parked. The larger size allows for more powerful brake application, ensuring that the vehicle remains stationary even on inclines or when parked for extended periods of time. Service brake chambers, on the other hand, are smaller and are responsible for providing the braking force during normal driving and stopping.

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115.

Explanation

not-available-via-ai

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116. The air loss rate on a towing vehicle with two or more trailers must not exceed?

Explanation

The correct answer is 41 kPa (6 psi) per minute. This means that the air loss rate on a towing vehicle with two or more trailers should not exceed 41 kPa or 6 psi per minute. This is important because if the air loss rate is too high, it can lead to a loss of braking power and control of the vehicle, which can be dangerous. Therefore, it is crucial to monitor and maintain the air pressure in the braking system to ensure safe towing operations.

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117. When a vehicle's service brakes fail to apply, emergency brakes can be applied by using the?

Explanation

The correct answer is the Spring brake control valve. When a vehicle's service brakes fail to apply, the spring brake control valve can be used to apply the emergency brakes. This valve controls the air pressure to the spring brakes, which are separate from the service brakes. By activating the spring brake control valve, the spring brakes are engaged, providing a backup braking system in case of failure of the service brakes.

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118. When testing air pressure build-up time, pressure must build from 587 to 690 kPa ( 85 to 100 psi ) within?

Explanation

The correct answer is 2 minutes. This means that when testing air pressure build-up time, the pressure must increase from 587 to 690 kPa (85 to 100 psi) within a time frame of 2 minutes.

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119. To test the low air warning device, the ignition switch must be turned on and air pressure must be?

Explanation

To test the low air warning device, the air pressure needs to be reduced from the normal operating range until the device activates. This means that the air pressure should be lowered from its usual level until the device is triggered and the warning is activated. By doing this, it can be ensured that the low air warning device is functioning properly and will alert the driver when the air pressure in the system is too low.

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120. While draining a vehicle's air tanks, the driver must watch the?

Explanation

When draining a vehicle's air tanks, it is important for the driver to watch for any abnormalities in the discharge from the air tank. This is because any abnormal discharge, such as excessive oil or water, could indicate a problem with the air system that needs to be addressed. By monitoring the discharge from the air tank, the driver can identify and fix any abnormalities before they cause further damage or affect the performance of the vehicle's air brakes.

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121. Air pressure is usually measured in

Explanation

Air pressure is typically measured in units of kilopascal (kPa) or pounds per square inch (psi). These units quantify the force exerted by the air molecules in a given area. kPa is the metric unit of pressure commonly used in scientific and engineering applications, while psi is the imperial unit often used in everyday contexts. Both units provide a measure of air pressure, with kPa being more widely used internationally and psi more commonly used in the United States.

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122. Trailer spring brakes must apply automatically when the?

Explanation

When the trailer supply valve is closed (pulled out), the trailer spring brakes must apply automatically. This is because the supply valve controls the flow of air from the tractor to the trailer's brake system. When the valve is closed, it cuts off the air supply, causing the spring brakes to engage and apply the brakes on the trailer. This is a safety feature that ensures the trailer remains stationary and prevents it from rolling or moving unintentionally.

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123. Each , type and size has a specific?

Explanation

The correct answer is "Adjustment limit" because each type and size of something has a specific limit to how much it can be adjusted. This means that there are certain boundaries or restrictions on how much you can adjust or modify something based on its type and size.

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124. Disc brake components include?

Explanation

Disc brake components include calipers and rotors. Calipers are responsible for applying pressure to the brake pads, which then press against the rotors to slow down or stop the vehicle. The rotors, also known as brake discs, are attached to the wheel and provide the surface for the brake pads to make contact with. Together, the calipers and rotors work in tandem to create the friction necessary for effective braking.

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125. 'S' cam brake components include?

Explanation

'S' cam brake components include camshafts and brake shoes. Camshafts are responsible for converting the linear motion of the brake chamber pushrod into the rotational motion needed to activate the brake shoes. Brake shoes are the components that press against the brake drums to create friction and stop the vehicle. Therefore, camshafts and brake shoes are the correct components included in 'S' cam brake systems.

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126. When , the driver must look for?

Explanation

The driver must look for insecure mounting bracket or fasteners while driving. This is important because if the mounting bracket or fasteners are not properly secured, it can lead to instability and potential hazards while driving. By checking for insecure mounting bracket or fasteners, the driver can ensure the safety and stability of the vehicle.

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127. Air compressor cut-in pressure must never be less than?

Explanation

The cut-in pressure of an air compressor refers to the minimum pressure at which the compressor starts running to build up the air pressure. It is important for the cut-in pressure to be set at a level that ensures the compressor starts operating efficiently without unnecessary cycling. Among the given options, 552 kPa (80 psi) is the most suitable cut-in pressure as it provides a balance between starting the compressor at a reasonable pressure and preventing excessive cycling.

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128. The normal range of air pressure in an air brake system is between

Explanation

The normal range of air pressure in an air brake system is between 552 932 kPa and 80 135 psi. This range is considered to be the standard operating pressure for air brakes. It is important for the air pressure to fall within this range to ensure the proper functioning of the brake system. If the pressure is too low, the brakes may not be able to effectively stop the vehicle, while if the pressure is too high, it can cause damage to the system. Therefore, maintaining the air pressure within this range is crucial for the safe operation of the air brake system.

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129. An air compressor governor should cut-in approximately 138 to 173 kPa (20 to 25 psi)?

Explanation

The correct answer is "Below cut-out pressure setting." This means that the air compressor governor should start operating and allow air to flow into the system when the pressure drops below the cut-out pressure setting. This ensures that the compressor kicks in and provides air when it is needed to maintain the desired pressure level.

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130. The points where the air compressor is turned on and off determine the normal operating pressure range of an air brake system. Cut-Out and Cut-In pressure is normally?

Explanation

Below the Cut-Out setting and must never be less than 552 kPa (80 psi)

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131. A tractor protection valve?

Explanation

The tractor protection valve is a safety device that prevents the loss of air from the towing vehicle. It is designed to automatically close and isolate the trailer supply line in the event of a break or leak in the line. This prevents air from escaping the towing vehicle, ensuring that the brakes and other pneumatic systems continue to function properly. By preventing air loss, the tractor protection valve helps maintain the overall safety and efficiency of the towing vehicle.

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132. When a trailer's service brakes fail to apply, the trailer spring brakes an be applied by using the?

Explanation

The trailer supply valve is used to apply the trailer spring brakes when the service brakes fail to apply. This valve allows the driver to manually activate the spring brakes, ensuring that the trailer can still be safely stopped even if the service brakes are not functioning properly.

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133. A trailer with spring brake priorty allows the trailer spring brakes to release before?

Explanation

A trailer with spring brake priority allows the trailer spring brakes to release before the trailer service brakes will operate. This means that when the towing vehicle's service brakes are applied, the trailer spring brakes will release first, allowing the trailer service brakes to engage and assist in slowing down or stopping the trailer. This prioritization ensures that the trailer's braking system is functioning properly and helps to prevent any potential issues or accidents while towing.

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134. Name the components of the?

Explanation

The components of the Spring Brake Clamp include the Diaphragm, Push Rod, Return Spring, Yoke, Clevis pin, Large coil spring, Spring Brake Diaphragm, Return spring, Service Brake Chamber, and Slack Adjuster.

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135. To test the , the driver must check for air exhausting from the?

Explanation

The correct answer is "Trailer service line with the trailer supply valve closed ( pulled out )". This is because when the trailer supply valve is closed, there should be no air exhausting from the trailer service line. This test is important to ensure that there are no leaks or issues with the trailer's air system.

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136. What air tanks should be drained first when during air tank maintenance?

Explanation

During air tank maintenance, it is important to drain the supply tank first. This is because the supply tank holds compressed air that is used for various functions in the system. By draining the supply tank first, any excess moisture, oil, or contaminants that may have accumulated can be removed, ensuring that the air supplied to the system is clean and dry. The wet tank should be drained next as it collects moisture and condensation from the compressed air system. By draining the wet tank, any accumulated water can be removed, preventing potential damage to the system and ensuring optimal performance.

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137. A tractor protection valve is defective if the trailer supply valve is closed ( pulled out ) and air exhausts from the?

Explanation

When the tractor protection valve is defective, it means that there is a malfunction in the valve's mechanism. In this case, if the trailer supply valve is closed (pulled out) and air exhausts from the trailer service line with the brake pedal pressed, it indicates that there is a problem with the valve. The trailer service line is the line that carries air from the tractor to the trailer's service brakes. Normally, when the brake pedal is pressed, air should not exhaust from the service line. Therefore, if air is exhausting from the service line in this situation, it suggests that the tractor protection valve is defective.

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138. The trailer hand valve is used to?

Explanation

The trailer hand valve is used to apply the trailer service brakes. This means that when the hand valve is activated, it will activate the brakes on the trailer, allowing the driver to slow down or stop the trailer independently from the towing vehicle.

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139. The normal range of air pressure in an air brake system is between

Explanation

The normal range of air pressure in an air brake system is between 552,932 kPa and 80,135 psi. This range is important to ensure proper functioning of the air brake system. If the pressure is too low, the brakes may not engage effectively, while if the pressure is too high, it can cause damage to the system. Therefore, maintaining the air pressure within this range is crucial for safe and efficient operation of the air brake system.

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140. The points where the air compressor is turned on and off determine the normal operating pressure range of an air brake system. Cut-Out and Cut-In pressure is normally?

Explanation

Below the Cut-Out setting and must never be less than 552 kPa (80 psi)

Submit
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Air compressor cut-in pressure must never be less than?
When inspecting the air compressor drive belt, the driver must look...
When an air brake system is defective you must?
When an air brake system is defective you must?
When an air brake brake system is defective you must?
When inspecting the, the driver must look for?
Drivers must be careful when conducting an inspection of the air brake...
A reliable method for inspecting brake adjustment on a brake having an...
When a low air pressure warning device activates, the driver must?
When a vehicle's brakes do not comply with the Ontario Highway...
When an air brake system is defective you must?
A reliable method for inspecting brake adjustment on a brake having an...
A vehicle's brakes must do more work when?
The minimum and maximum pressure settings prescribed in the Ontario...
A reliable method for inspecting brake adjustment on a brake having an...
When measuring the applied push rod stroke on brake having exposed...
A reliable method for inspecting brake adjustment on a brake having an...
When a driver finds a brake that is out of adjustment?
Air brake systems must comply with the Ontario Highway Traffic Act and...
Disc brake components include?
The low air warning device must activate before air pressure drops to?
The air that exhausts from an air brake system can carry?
Air brake systems must comply with the Ontario Highway Traffic Act and...
When an air brake system is defective you must?
When measuring the applied push rod stroke on brakes having push rods,...
Anti-lock braking systems (ABS) use warning indicator lights to...
When a vehicle's brakes do not comply with the Ontario Highway...
When conducting an inspection of the air brake system, the vehicle...
A governor controls air compressor?
Repair and re-adjustment of all types air brakes may be performed by?
When inspecting visible air brake hoes and tubes, the driver must...
A brake having an exposed push rod is out of adjustment when?
The air loss rate on a single vehicle ( bus, tractor or truck ) must...
When inspecting the air tanks, the driver must look for?
An air tank drain valve that fails to function?
A tractor protection valve is defective if the trailer supply valve is...
Air compressor cut-in pressure must never be less than?
The air loss rate on a towing vehicle with two or more trailers must...
The air loss rate on a single vehicle (Bus, Tractor or Truck) must not...
A vehicle should only be driven when air pressure is in the normal...
Disc brake components include?
Hydraulic systems use brake?
The air loss rate on a towing vehicle with two or more trailers must...
A tractor protection valve is defective if the trailer supply valve is...
When air loss from an air brake system exceeds the prescribed limits?
When inspecting visible air brake hoses and tubes, the driver check...
Repair and re-adjustment of all types of air brakes may be performed...
The brake systems on  most large commerical vehicles use?
The low air warning device must activate before air pressure drops to?
Driving a vehicle with an air brake system that is outside the normal...
To prevent vehicle movement during an inspection of the air brake...
Brake fade can result from?
When trailer couplers or gladhands are cross-connected?
When inspecting ,  the driver must look for?
High brakes temperature can result from?
Drivers must be careful  when conducting  an inspection of...
Using anti-lock braking systems (ABS) to prevent the wheels from...
When inspecting the , the driver must look for?
The vehicle fails the test when the cut-out pressure setting is higher...
When inspecting the foundation brake components, the driver must look...
When air brake system pressure drops below 414 kPa (60 psi), the...
A spring brake control valve is normally?
When , air pressure must be between?
The part inside a spring brake chamber that can be hazardous is the?
A properly functioning air brake system?
A tractor protection valve is defective if the trailer supply valve is...
The compressed air in an air brake system is stored in?
Brakes convert the energy of a moving vehicle into?
When inspecting the brake chambers on each side of a steering axle,...
When brake chamber push rod stoke exceeds the adjustment limit?
Air tanks must be drained regularly because?
To check the air pressure in a vehicle's air brake system, a...
Air compressors are powered directly by the engine or by using?
To test the low air warning device, the ignition switch must be turned...
A reliable method for inspecting brake adjustment on a brake...
The low air warning device must activate before air pressure drops to?
Vehicles with air brakes must have air pressure gauges that indicate...
Trailer couplers or 'gladhands' are usually?
A vehicle's brakes must do more work when?
The vehicle passes the test when the cut-out pressure setting is...
Alcohol evaporators may be used to?
When inspecting the air tanks, the driver must look for?
If a vehicle moves while the spring brakes are applied, the vehicle...
The air loss rate on a single vehicle (bus, tractor or truck) must not...
 Side view and underside view of a conventional 18-wheeler...
To test air pressure build-up time, the engine must be running at?
A brake having an exposed push rod is out of adjustment when?
A trailer supply valve is usually?
The brake pedal in an air brake system is used to?
Wedge brake components include?
Trailer couplers or gladhands are used to connect the?
When air brakes are applied or released, the brakes will respond?
When a vehicle's brakes are out of adjustment?
The brake pedal in an air brake system is used to?
Air compressors?
When measuring the applied push rod stroke on brakes having exposed...
Safety valves prevent?
An air tank drain valve that fails to function?
The points where the air compressor is turned on and off determine the...
The normal range of air pressure in an air brake system is between
A vehicle's brakes must do more work when?
The normal range of air pressure in an air brake system is between
The points where the air compressor is turned on and off determine the...
The type of air brake components on most large commerical vehicles are...
The ability of the brakes to stop a vehicle
The air brake system on a trailer includes?
The points where the air compressor is turned on and off determine the...
The normal operating pressure range for air brake systems is?
Are?
Air brake chamber push rod stroke is the result of?
Wedge brake components include?
When a spring brake chamber has been disabled by a 'caging...
An air dryer removes moisture, which is excelled when the?
Spring brake chambers?
The air loss rate on a towing vehicle with two or more trailers must...
When a vehicle's service brakes fail to apply,...
When testing air pressure build-up time, pressure must build from 587...
To test the low air warning device, the ignition switch must be turned...
While draining a vehicle's air tanks, the driver must watch the?
Air pressure is usually measured in
Trailer spring brakes must apply automatically when the?
Each , type and size has a specific?
Disc brake components include?
'S' cam brake components include?
When , the driver must look for?
Air compressor cut-in pressure must never be less than?
The normal range of air pressure in an air brake system is between
An air compressor governor should cut-in approximately 138 to 173 kPa...
The points where the air compressor is turned on and off determine the...
A tractor protection valve?
When a trailer's service brakes fail to apply, the trailer spring...
A trailer with spring brake priorty allows the trailer spring brakes...
Name the components of the?
To test the , the driver must check for air exhausting from the?
What air tanks should be drained first when during air tank...
A tractor protection valve is defective if the trailer supply valve is...
The trailer hand valve is used to?
The normal range of air pressure in an air brake system is between
The points where the air compressor is turned on and off determine the...
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