Tennessee CDL DMV Knowledge Test Class A 2

To test a parking brake, you should fasten your safety belt, set the parking brake for the power unit, release the trailer parking brake (if applicable), place the vehicle in low gear, and attempt to pull forward against the parking brake. If the parking brake does not hold while you are attempting to pull forward against it, the brake is faulty and must be fixed.

When inspecting a vehicle, you should verify that your dual tires do not come into contact with one another, or with any other part of the vehicle.

Air storage tanks are used to hold compressed air. The number and size of air tanks in an air brake system varies among vehicles.

In bad weather, particularly when visibility is poor, it is common for automobile drivers to follow closely behind trucks. Open up the distance between your vehicle and the vehicle in front of you if you are being followed too closely.

Anti-Lock Braking Systems (ABS) are compatible with air braking systems. ABS helps maintain control of a vehicle and prevents the wheels from locking up during hard braking on slippery surfaces. ABS can still provide benefits even if is present on only one axle.

If brakes are overused, they can become too hot. This overheating causes them to fade, making them less effective at slowing the vehicle.

When driving at dawn, at dusk, or in inclement weather, you should use your headlights on their low beam setting to increase your visibility.

If your drive wheels begin to spin while accelerating on a surface with poor traction, you should remove your foot from the accelerator.

For safe driving, it is important to be aware of what is happening on all sides of your vehicle. A vehicle should have mirrors on both sides, which should be checked regularly.

A dual air brake system is made up of two separate air brake systems. The systems share a single set of brake controls, but each has its own air tanks, hoses, and lines.

If you begin to feel tired while driving, the only safe action to take is to stop and get some sleep. Trying to fight the fatigue and press on is very dangerous and can result in a fatal crash. You should not rely on artificial stimulants; these may help keep you awake a while longer, but they won't make you more alert.

Be sure to thoroughly inspect your tires before a trip. Tire sizes should not be mismatched, and tires should not be cut, cracked, or otherwise damaged in any way.

In an air brake system, the air compressor governor controls when the air compressor pumps air into the air storage tanks.

Always turn on your four-way emergency flashers if you must park on the side of the road. This is especially important when traveling at night.

It is important to know the maximum air loss rate that is safe for your specific vehicle. A single vehicle with air brakes should have a leakage rate no higher than 3 psi in a minute during an applied leakage test.

Check hydraulic brakes by pumping the brake pedal three times before applying firm pressure to the pedal for five seconds. The pedal should not move. If it does, there may be a leak or some other problem in the braking system.

If your vehicle gets stuck on railroad tracks, immediately exit the vehicle and get away from the tracks. Check signs or signal housing at the crossing for emergency contact information. Call the emergency contact or call 911.

Skids caused by acceleration frequently occur on slippery road surfaces. These skids can generally be resolved by the driver removing their foot from the accelerator.

Because air pressure can eventually leak away, the emergency brakes in an air brake system must be held on by mechanical force.

The parking brake should be applied when leaving your vehicle.

Potential problems to check for when inspecting brakes include cracked drums; shoes or pads with oil, grease, or brake fluid on them; and shoes that are missing, broken, or worn dangerously thin.

Blocking and bracing are used to prevent cargo from shifting in transit. Blocking is used in the front, in the back, and on the sides of a piece of cargo to prevent movement. Bracing prevents movement by reaching from the upper portion of a piece of cargo to the floor and sides of the cargo compartment.

In a vehicle with air brakes, never push the brake pedal down when the spring brakes are activated. The combined force of the springs and the pressure of the air brakes could damage the brakes.

A broken exhaust system is extremely hazardous because it can permit poisonous fumes to enter the vehicle's cab or sleeper berth.

In an air brake system, the air storage tanks are equipped with drains to allow water and compressor oil to be removed. The water and oil can damage the brakes if left to accumulate in the system.

When inspecting your tires, verify that there is tread depth of at least 4/32 of an inch in every major groove on the front tires and tread depth of at least 2/32 of an inch in grooves on the other tires. Be sure that your tires are not too worn, are not cracked, have proper air pressure, and are all equally sized.

An operator should drive with care when transporting a cargo of hanging meat. Such a load is unstable, both because it has a high center of gravity and because the swinging of the meat can affect the driver's handling of the vehicle.

Blocking and bracing are techniques to keep cargo from shifting in transit. A piece of cargo should be blocked to its front, back, and/or sides to prevent movement.

Railroad crossings that are not controlled by any type of traffic control device are known as passive crossings. The decision to proceed across tracks at a passive crossing is entirely up to the driver.

If you must stop on the shoulder of a road, put out your emergency warning devices within 10 minutes of stopping. When pulling off the road to stop, be sure to turn on your four-way emergency flashers.

To warn drivers behind you that you are about to slow down, it may be a good idea to first lightly tap your brake pedal a few times to make the brake lights flash.

Driving at night is more dangerous than driving during the day because hazards become more difficult to see in the dark.

Do not assume that posted height clearances are accurate. If the road was repaved after the sign was posted, or if there is packed snow on the ground, the actual height of the opening may be different than what is indicated. If you are not confident that your vehicle will be able to safely clear an upcoming bridge or overpass, you should slow down and find another path, if possible.

At times when visibility is low, you should turn your headlights on to the low beam setting. If you are having a difficult time seeing others, they are probably having a difficult time seeing you.

You should reduce your speed by about one-third when driving on a wet road. It can be difficult to stop or turn when operating on a slippery surface, so you must adjust your speed to drive safely under such conditions.