A low air pressure warning signal should activate:
Answers
When tank pressure falls below 120 psi.
When tank pressure falls below 55 psi.
When tank pressure falls below 10 psi.
When tank pressure falls below 5 psi.
The Correct Answer and Explanation is :
The correct answer is: When tank pressure falls below 55 psi.
Explanation:
A low air pressure warning signal is an essential safety feature in commercial and heavy-duty vehicles equipped with air brakes. The purpose of this warning system is to alert the driver when the air pressure in the brake system becomes dangerously low, indicating that the brakes might not function effectively. Proper air pressure levels are crucial for ensuring that the braking system operates safely and reliably.
In most air brake systems, the low air pressure warning system is designed to activate when the air pressure drops below 55 psi (pounds per square inch). This is a predetermined threshold set to ensure the driver is aware of potential issues before they lead to braking failure.
When the air pressure falls to or below 55 psi, a warning signal—usually a red light and/or an audible buzzer—alerts the driver to take immediate action. This system acts as an early warning, allowing the driver to pull over and address the issue before it compromises vehicle safety. It is important to note that the 55 psi threshold is not the point at which the brakes will stop functioning; rather, it is an indicator that there is insufficient pressure for optimal brake performance.
The other options provided are not correct because:
- 120 psi is typically considered a normal operating pressure range for most air brake systems, and signaling at this level would be unnecessary.
- 10 psi and 5 psi are far below the point at which the system is designed to issue a warning. At these low levels, the vehicle’s braking system would already be compromised, making it too late for the driver to respond effectively.
Overall, a low air pressure warning at 55 psi helps maintain a balance between ensuring driver awareness and providing enough time for corrective measures to be taken, thus preventing brake system failure and ensuring road safety.