Montana CDL DMV Knowledge Test Class B 2

The most common type of foundation brake is an s-cam drum brake.

When inspecting your vehicle's engine, check the belts for tightness and excessive wear. The amount of "give" that is safe for each belt in a given engine will vary, so learn what is appropriate for your vehicle.

Hydroplaning is an effect in which a vehicle's tires lose traction with the surface of the road and instead glide along a layer of water. There does not have to be much water on the road for this to occur.

It is important to observe other drivers' behaviors and identify clues that indicate when person could be driving impaired. Drivers who have had too much to drink, are sleepy, are on drugs, or are ill can present hazards to other drivers. A person driving with their window open in cold weather may be impaired.

One way to know when it is time to shift gears is to learn your vehicle's operating rpm range. You should shift up when your engine reaches the top of that range. You can also learn which speeds each gear is good for and shift up based on your speedometer.

When accelerating, speed up smoothly and gradually so your vehicle does not jerk. Rough acceleration can cause mechanical damage.

"Axle weight" refers to the weight transmitted to the ground by one axle or one set of axles.

During the CDL vehicle inspection test, you must be able to inspect your vehicle and explain to the examiner what you are inspecting and why.

Factors that can affect your vehicle's stopping distance include driving speed, the vehicle's weight, and the slipperiness of the road surface.

It is important to know the maximum air loss rate that is safe for your specific vehicle. A double combination vehicle should have a leakage rate no higher than 4 psi in a minute during an applied leakage test.

Always drive cautiously around a stopped bus. Passengers may cross in front of or behind it, and the bus may prevent them from seeing your vehicle.

When approaching your vehicle, you should check under the vehicle for fresh oil, coolant, grease, or fuel leaks. Spotting any of these before a trip is a cause for concern.

While swerving can sometimes be the safest way to handle a hazard on the roadway, doing so is not without risk. Top-heavy vehicles and tractors with multiple trailers may flip over in a swerve.

To improve visibility, you should use high beam headlights at night where it is safe and legal to do so. However, the glare from high beam lights can blind other drivers. You should dim your lights to their low beam setting when driving within 500 feet of an approaching vehicle.

Passing parked delivery or postal trucks can be dangerous because the driver may be in a hurry and pull into traffic without warning, or may they suddenly step out of the vehicle without checking for other traffic.

For your own safety, when placing reflective warning triangles, you should carry them between your body and the oncoming traffic.

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 the low pressure warning signal activates while you are driving, it is important that you safely exit the roadway as soon as possible and park your vehicle. If the air pressure gets too low, the brakes will no longer work well enough for you to stop safely.

Most cases of hydraulic brake failure come from one of two causes. The brakes may fail due to a loss of hydraulic pressure or due to overuse on long hills, causing the brakes to fade.

When approaching a curve during the on-road driving test, you should thoroughly check traffic in all directions. Before entering the curve, reduce your speed sufficiently so that further braking or shifting is not required. Keep your vehicle in its lane and continue checking traffic in all directions.

On a wet road, it is possible for a vehicle's tires to lose traction with the road surface and begin to glide along on the layer of water. This is referred to as hydroplaning. Hydroplaning can occur at speeds as low as 30 mph.

If you are approaching a traffic light that has been green for a long time, there is a good chance that it will turn yellow before you reach it. Start slowing down and be ready to stop.

Bridges usually freeze before the rest of the road. You should be especially careful when crossing bridges if the temperature is near the freezing point.

A broken exhaust system can let poisonous fumes into a vehicle's cab or sleeper berth. Be sure to inspect your exhaust system for any loose, broken, or missing parts.

Focusing on your mirrors for too long can be dangerous because you will have traveled a substantial distance without looking at the road ahead.

When inspecting an enclosed trailer as a part of the vehicle inspection test, check the front area of the trailer for signs of damage, such as cracks, bulges, or holes.

Tar in road pavement often rises to the surface of the road, or "bleeds," in very hot weather. Watch for such areas because they can be very slippery.

To avoid hitting vehicles behind you, you must ensure that your vehicle will not roll backward when you start moving forward from a stopped position.

Driving at night is more dangerous than driving during the day. It is more difficult for drivers to see hazards, the glare of headlights can affect drivers' vision, and there are more fatigued and impaired drivers on the road.

You will be denied a hazardous materials endorsement, or lose an existing endorsement, if you renounce your U.S. citizenship; are not a lawful permanent U.S. resident; are wanted for, indicted for, or convicted of certain felonies; are judged mentally defective or are committed to a mental institution; or are deemed by the Transportation Security Administration (TSA) to pose a security threat.

If a tractor-trailer is so equipped, the trailer brake hand valve can be used to stop the vehicle from rolling back when being started from a stop.

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

Gross Vehicle Weight Rating (GVWR) is the weight specified by the manufacturer as the maximum weight of a single vehicle and its load.

An air brake system has a safety relief valve, which releases air from the tanks if the pressure gets too high. If the valve must operate, something in the system is wrong and should be addressed by a mechanic.

Sending and reading text messages while driving is prohibited.