What psi of air is required in the rear air system for the suspension dump valve to function?

Answer: C — 70 psi

The rear air system requires a minimum pressure of 70 psi for the suspension dump valve to function correctly. This specific pressure threshold ensures that the air suspension system has enough force to operate effectively. When the air pressure reaches this level, the dump valve can engage, allowing the suspension system to release air, which is essential for lowering the vehicle for loading or unloading. Having inadequate pressure in the system can prevent the dump valve from operating, which may result in improper vehicle handling, difficulty in loading, and potentially unsafe driving conditions. Therefore, understanding the importance of maintaining the appropriate psi in the rear air system is crucial for the effective operation of the air suspension system.