CDL General Knowledge Practice Test 2026 - Free CDL Practice Questions and Study Guide

If your brakes begin to fail while driving downhill, shifting to a lower gear and using engine braking is the appropriate response. This technique helps to control your speed by leveraging the engine’s resistance instead of relying solely on the brakes, which may no longer be effective.

When you shift to a lower gear, the engine works harder to slow down the vehicle, thus aiding in deceleration. This method is especially important in a heavy vehicle, as it helps to prevent a buildup of speed that can occur when careening downhill without adequate braking power. Utilizing engine braking not only helps to manage speed more effectively but also reduces the risk of overheating the brakes, which can lead to complete brake failure.

The other responses do not provide a safe or effective solution to braking failure. Continuously applying the brakes can exacerbate the problem and might lead to further brake overheating. Ignoring the issue until reaching the bottom can be extremely dangerous, as it does not address the immediate safety concerns posed by losing braking ability. Steering straight and hoping for the best is a passive and highly risky approach that overlooks the necessity of taking control of the situation proactively.