Louisiana Class D Chauffeur's License Practice Test

The primary purpose of the parking brake in an air brake system is to secure the vehicle when it is stationary. This function is crucial for safety, as it prevents the vehicle from rolling away when parked. The parking brake, often referred to as the hand brake or emergency brake, is designed to operate independently of the main air brake system, ensuring that the vehicle remains immobilized even in the event of a failure in the primary braking system. It is important to engage the parking brake whenever the vehicle is left unattended to ensure it stays in place, especially on inclines or slippery surfaces where the potential for movement is higher.