Air Brake Practice Test

You can use pressure from a separate tank for what purpose if your truck has dual control valves?

1. Try to balance the service brakes as you're driving

2. Remain parked without exhausting the service air pressure

3. Apply additional stopping pressure if the main tank is low

4. Let go of the emergency brakes to move short distances

The correct answer is: Let go of the emergency brakes to move short distances

Using pressure from a separate tank with dual control valves primarily serves the purpose of managing the braking system's functionality more effectively. When a vehicle is fitted with dual control valves, it allows for the independent operation of the braking system, which enhances safety and control. When the correct choice is considered, the action of allowing the driver to release the emergency brakes to move short distances is significant. In scenarios where the emergency brakes are engaged, utilizing pressure from an auxiliary tank can effectively disengage these brakes without risking the vehicle’s safety. This can be particularly useful for maneuvering the vehicle for short distances, such as repositioning or parking, while still maintaining adequate control over the braking system. Moreover, while there are various functions of pressure from a separate tank, such as potentially aiding in various braking scenarios or preventing service air pressure from exhausting, the pivotal role here is the ability to release the emergency brakes, thereby ensuring the vehicle can be moved as needed.