CDL Tanker Endorsement Practice Exam

When should you drain your air tanks if you do not have an automatic tank drain?

1. At the end of each working day

2. Every week on Tuesday

3. Before starting the engine

4. After each trip

The correct answer is: At the end of each working day

Draining the air tanks at the end of each working day is essential for maintaining the overall functionality and safety of the vehicle. Air tanks can accumulate moisture from the air, which can lead to corrosion, brake issues, and other complications if not addressed. By draining the tanks daily, you help prevent the buildup of water and contaminants, thus ensuring that the air supply system remains clean and functional. This practice enhances the reliability of the braking system and minimizes the risk of malfunction due to moisture, particularly in colder weather where freezing can occur. Choosing to drain the tanks on a fixed schedule, such as every week or only before starting the engine, does not account for the variable conditions that can lead to differing amounts of moisture accumulation. These methods may not adequately address the issue and could allow problems to develop over time. Additionally, draining air tanks after each trip may be unnecessary and time-consuming, as moisture is more likely to build up during the day’s operation rather than in the interim periods between trips. Therefore, the best practice is to drain the air tanks at the end of each working day to ensure optimal performance and safety.