Alabama CDL Knowledge Test Class A: Practice Test

During the external inspection portion of the pre-trip vehicle inspection test, you must verify that the steering box is securely mounted and not leaking.

Some older vehicles with air brakes have front brake limiting valves. These valves were intended to reduce the risk of front wheels skidding. However, research has shown that such devices are unnecessary, so they should be left in the "normal" position.

When inspecting a vehicle with a dual air brake system, you should wait for air pressure to build from 85 to 100 psi in both the primary and secondary systems. This should take about 45 seconds.

Always slow down before entering a foggy area. Use low beam headlights, avoid passing others, and avoid stopping on the side of the roadway. It is safest to completely avoid driving under foggy conditions, if possible.

If you find yourself being tailgated by another driver, you should increase your following distance and avoid making quick moves. Increasing your speed may only result in the other driver continuing to tailgate you at a higher speed. Do not turn on your taillights or flash your brake lights at the other driver.

In construction zones, do not exceed the posted safe sped limit. Slow down even more when workers are near the roadway.

Both systems in a dual air brake system share a single air compressor. If the air compressor is damaged, neither system will be able to operate properly.

Drum brakes are attached to the wheels and located on the axles of a vehicle. The braking mechanisms that cause the vehicle to stop can be found inside of a drum brake.

If you begin to feel drowsy while driving, the best thing to do is to stop and get some sleep. A driver trying to push on and finish a trip while fatigued is a major cause of fatal accidents.