During an emergency stop, at what application pressure does the steering axle begin to receive some braking pressure?

In a heavy vehicle equipped with air brake systems, it is essential to understand how the system responds during an emergency stop. The steering axle, which typically includes the front wheels, starts receiving braking pressure at a specific point in the application of air pressure.

When the air pressure begins to build up in the brake system, it is generally around the range of 5 to 15 p.s.i. that braking pressure is first applied to the steering axle. This initial pressure helps to engage the brakes primarily at the front, allowing for better control during an emergency maneuver. This is crucial because effective steering is maintained as the vehicle begins to slow down, which is vital in avoiding potential accidents.

Recognizing the pressure ranges that trigger brake engagement can aid drivers in understanding how to maximize control and stability when bringing a heavy vehicle to a stop, particularly in emergency situations. Additionally, pressures below this range do not allow sufficient brake activation on the steering axle, potentially leading to a loss of control. Thus, the primary reason for identifying the correct application pressure is to ensure driver awareness of the vehicle's braking system and its response during critical driving scenarios.