Oklahoma CDL Permit Test - Knowledge Test Class A

Compressed air in an air brake system usually contains a certain amount of water and compressor oil. The water and oil can damage the brakes if left to accumulate in the system. Tanks must be drained regularly to remove this build-up.

If you observe a crash involving an aggressive driver, you should stop a safe distance from the crash scene, wait for police to arrive, and inform them of the aggressive behavior you witnessed.

Poorly balanced weight in a trailer can make handling unsafe. For example, either too little or too much weight on the front axle can make a vehicle difficult to steer. Weight should be distributed evenly from front to back and from side to side. It should be distributed as low as possible.

All commercial motor vehicles are required to be equipped with the proper emergency equipment. This may include spare electrical fuses; three red reflective triangles, six fuses, or three liquid burning flares; and at least one properly charged and rated fire extinguisher.

Check your engine during the pre-trip inspection. After starting the engine, you should listen for unusual noises.

In general, a smaller vehicle will be able to come to a complete stop faster than a larger vehicle. Keep this in mind when determining your following distance.

If you must stop on the side of the road, make sure to use your four-way emergency flashers. This is particularly important at night.