New Mexico CDL DMV Knowledge Test Class A 2

The safety relief valve in an air brake system releases air if necessary to prevent pressure in the system from becoming too high. If the valve starts releasing air, there is something wrong. Have a mechanic fix the problem.

It is essential that a vehicle's engine have adequate oil pressure. An engine can be destroyed rapidly if it is run without oil.

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.

For safe operation, a commercial motor vehicle needs a tread depth of 4/32 of an inch in every major groove on the front tires, and a tread depth of 2/32 of an inch on other tires.

Check each slack adjuster after parking on level ground, setting wheel chocks, and disengaging the parking brake. Pull the slack adjusters to make sure they do not move more than about one inch from where the push rod is attached. If they move more than one inch, they may be out of adjustment and will need to be fixed.

When performing a static leakage test on a triple combination vehicle with air brakes, the leakage rate should be no more than 5 psi in one minute. If the air leaks from the air brake system at a quicker rate, the vehicle should not be driven because something likely needs to be repaired.

In the event of a vehicle fire, you should leave the road and stop in an open area. Do not pull into a service station as fuels at the service station could catch fire. Report the fire and your location to emergency services.

Strong winds can make it difficult to keep a vehicle in its proper lane. Strong wind can be a particular problem when a vehicle is being driven out of a tunnel.

Even if they did not load or secure the cargo themselves, the driver of a vehicle is responsible for inspecting the cargo and ensuring that it is properly secured.

Cargo and its securement must be inspected every time you take a break during a trip. Be sure to inspect the cargo at least every 150 miles.

A cargo of hanging meat can be very unstable, both because the meat swings about in transit and because its center of gravity is high.

If you think the road surface may be becoming icy but you are not certain, you can open your window and feel the front of the side mirror, mirror support, or antenna. If ice has formed on any of these items, the road is likely becoming icy as well.

Cargo should be restrained by at least one tie-down for every 10 feet of cargo. However, all cargo should have at least two tie-downs, no matter the size of the cargo.

If you are convicted of any kind of traffic violation, in any type of vehicle, you must notify your employer within 30 days. You must also inform your motor vehicle licensing agency of the violation within 30 days if the conviction happened in another jurisdiction. This rule does not apply to parking infractions.

In a dual air brake system, either the front or rear brakes will not be fully operable if one of the air systems gets too low on pressure. If the air pressure in either tank gets too low while you are driving, you should exit the road and park as soon as possible.

Using a hand-held mobile telephone while operating a CMV is both illegal and dangerous.

Black ice is a thin layer of ice that is clear enough for the road surface to be seen through it. A road covered in black ice may look like it is merely wet. You should be very careful when temperatures are below freezing and the road looks wet.

Wheels or rims that have had welding repairs are not safe to be used.

Always use your turn signals and check your mirrors when changing lanes.

If you are asked to alley dock, you should first pull past the alley and stop your vehicle in a position that is parallel to the outer boundary. From there, you should back your vehicle entirely into the alley parking area. Your vehicle should be parked in a straight position within the boundaries of the parking space.

If you are asked to complete an offset back/left parking maneuver, you should first pull straight forward, then back up to the left. Your vehicle must be parked completely within the boundaries of the parking space.

Regularly check mirrors on both sides of your vehicle while driving. It is important to be aware of what is happening behind and to the sides of your vehicle.

Factors that can affect stopping distance include the vehicle's speed, its weight, and the traction provided by the road surface.

Cargo inside a trailer must be secured appropriately to prevent it from shifting in transit.

During the pre-trip vehicle inspection test, you will be asked to check the power steering, water pump, alternator, and air compressor belts, if the vehicle is equipped.

If a heavy load prevents your vehicle from keeping up with the speed of other traffic, you should stay in the right lane.

To avoid a loss of control, you should accelerate slowly when driving in poor-traction conditions, such as rain or snow.

Pre-trip inspections should be conducted in the same way every time. This will reinforce the steps, making it less likely that you will forget to inspect something important.

During the vehicle inspection test, you will be required to do a complete inspection of your vehicle. During this inspection, you must explain to the examiner what you are inspecting and why you are inspecting those items.

Alcohol impairs a number of basic functions necessary for safe driving, including muscle coordination, reaction time, depth perception, and night vision. Operating a motor vehicle while under the influence of alcohol is both illegal and dangerous.

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.

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.

Over-length, over-width, and/or overweight loads may require special permits from the Department of Transportation.

Placards must be placed on the front, the rear, and both sides of a vehicle carrying hazardous cargo. They must be readable from any direction.

If you must use a mobile phone while driving, it must be in close proximity to you and easily reachable while you are securely fastened into your seat. It is dangerous and non-compliant to unsafely reach for a mobile phone, even if you plan to use a hands-free feature when speaking on the phone.