In a dual air brake system, air pressure should build from 85 to 100 psi within __ seconds.
Answers
25
10
45
The Correct Answer and Explanation is :
The correct answer is 45 seconds.
In a dual air brake system, air pressure should build from 85 to 100 psi within 45 seconds. This is a standard requirement for the safe operation of commercial vehicles such as trucks and buses, ensuring that the air brakes are fully operational before the vehicle is put into service.
Explanation:
A dual air brake system consists of two separate air brake circuits: the primary and secondary circuits. These circuits serve to provide air pressure to the vehicle’s braking system, and each circuit has its own air compressor, air tank, and brake lines. The system uses compressed air to operate the brakes, and it is essential that the air pressure in these circuits build to the required levels for safe braking performance.
When the air brake system is activated, air pressure begins to build up in both the primary and secondary circuits. The required minimum pressure to operate the brakes effectively is typically 100 psi (pounds per square inch). Therefore, the system needs to build air pressure from a lower value (typically around 85 psi) to 100 psi.
The 45-second requirement ensures that the vehicle’s air compressor is functioning properly and the air tanks are capable of building sufficient pressure in a reasonable amount of time. If the pressure does not build within this time frame, it could indicate a problem with the compressor, air leaks, or other system components, which can compromise braking efficiency and safety.
In practice, the system should reach 100 psi from 85 psi within 45 seconds under normal conditions. If this does not occur, the driver should inspect the system for issues such as faulty valves, leaks, or compressor malfunctions, as these can prevent the air pressure from building properly and could lead to brake failure. The 45-second standard is designed to ensure that the vehicle can achieve proper brake pressure quickly before it is driven, preventing potential safety hazards on the road.