Georgia Commercial Driver License Practice Test

What should a driver do before operating a vehicle with a dual brake system?

1. Inspect the entire brake system

2. Wait for the air compressor to build up a minimum of 100 psi in both systems

3. Check for brake fluid levels

4. Engage the parking brake

The correct answer is: Wait for the air compressor to build up a minimum of 100 psi in both systems

Before operating a vehicle with a dual brake system, it is crucial for the driver to wait for the air compressor to build up a minimum of 100 psi in both systems. This step is vital because a dual brake system typically consists of two separate brake circuits that work together to ensure safe braking performance. If the air pressure is insufficient, the brakes may not function properly, which could lead to decreased braking ability or even brake failure during operation. The requirement of reaching at least 100 psi in both brake systems ensures that the air brakes are sufficiently charged and ready to respond effectively upon application. This is a standard safety procedure designed to prevent accidents and ensure vehicle control, especially under heavy loads or driving conditions that require reliable braking. Other options, while important aspects of vehicle safety checks, do not specifically pertain to the unique requirements of operating a dual brake system. For example, inspecting the entire brake system and checking for brake fluid levels are important but do not address the critical need for adequate air pressure in an air brake system specifically before driving. Engaging the parking brake is a good practice but does not pertain directly to the operation readiness of the dual brake system in terms of air pressure.