CDL Tanker Endorsement Practice Exam

What is the safest way to brake to control surge in a tanker?

1. Apply the brakes suddenly

2. Keep a steady foot on the brake and avoid releasing it too soon

3. Use the engine to slow down before braking

4. Brake intermittently to control speed

The correct answer is: Keep a steady foot on the brake and avoid releasing it too soon

Using a steady foot on the brake and avoiding releasing it too soon is the safest approach to control surge in a tanker. When driving a tanker, the liquid cargo shifts during acceleration, deceleration, and cornering, which can create surge—a forward and backward motion of the liquid that affects vehicle stability. Maintaining a constant pressure on the brakes helps manage this movement effectively. Sudden braking can cause the liquid to surge forward forcefully, which can lead to loss of control or imbalance in the vehicle. By keeping a steady brake pressure, the driver can gradually manage the surge, allowing the liquid to slow down in a controlled manner rather than creating abrupt shifts in momentum. While the use of the engine to slow down before braking can be a helpful technique, it does not provide the direct, controlled braking force needed to mitigate surge as effectively as maintaining consistent brake pressure. Intermittent braking can increase the risk of surge due to the varying forces applied to the truck and the liquid. Therefore, utilizing a steady pressure on the brake is the most effective way to maintain control over the tanker’s dynamics during braking.