In a vehicle with dual air brakes, what happens if one system is low on pressure?

Question

In a dual air brake system, if one of the air systems gets very low on pressure, either the front or rear brakes will not be operating fully. You should bring your vehicle to a safe stop and have the air system repaired.

Accepted Answer

The front or rear brakes may not work properly.

Answer

The air from the other system will be used to supplement the system with the low pressure.

Answer

All brakes will be inoperable.

Answer

The low system will use an auxiliary system to fill the tank.