Air Brakes Endorsement Test | Mississippi 2025 #1

Train for FREE online with our Mississippi CDL air brake test. The official exam test consists of several obligatory parts, with all of them checking your knowledge of different blocks of road rules. If you need to obtain a MS Class A/Class B driver license in 2025, practice as much as possible. Free sample tests published on our website will help you check and improve your knowledge and boost your grades. Please bear in mind that the requirements for CDL may vary from state to state.

Number of Question 25

Passing Score 20

Number of Tests 20

1 . Spring brakes come on:

When too much air pressure is lost.

When a control on the dashboard is activated.

When the tires have minimal tread depth.

When the brakes are noisy.

Spring brakes come on automatically when air pressure drops to an unsafe psi level. Instead of waiting for the spring brakes to automatically activate, you should safely exit the road as soon as you notice the low pressure warning signal and bring your vehicle to a stop while you are still able to control the brakes.

2 . In a dual air brake system, if one air system is very low on pressure:

None of the brakes will work at all.

Either the front or rear brakes will not be fully operable.

There is usually no noticeable effect.

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.

3 . What is brake lag?

The time required for the brakes to work after the brake pedal is pushed

The distance between the brake pedal’s resting position and the floor

The amount of air pressure used to stop a vehicle

How faded the brakes are

Because air takes time to flow through the air lines to the brakes, air brakes cannot begin working instantly. There is often a brake lag of at least one-half of a second between the moment the brake pedal is pressed and the moment the brakes begin to work. On vehicles with hydraulic brakes, the brakes work instantly when the pedal is pressed.

4 . Some air brake systems use alcohol:

To reduce the risk of ice forming in air brake valves.

To make the compressor run more efficiently.

To lubricate parts of the braking system.

To reduce the risk of rust forming on air brake valves.

Some air brake systems contain an alcohol evaporator. This device introduces alcohol into the braking system to inhibit the formation of ice.

5 . What do anti-lock brakes do?

Help a driver avoid wheel lockup

Lock up the front wheels

Prevent a vehicle from accelerating while traveling uphill

Prevent a vehicle from accelerating while traveling downhill

The function of an Anti-Lock Braking System (ABS) is to prevent the vehicle's wheels from locking up from hard brake application.

6 . If using air tanks with manually operated drains, how often should you drain the tanks?

Every day

Once a week

Once a month

Once every six months

In an air brake system with manually operated drains, the tanks should be drained at the end of each day of driving.

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2025 Mississippi | Frequently Asked Questions

To secure a CDL Doubles/Triples endorsement in Mississippi, you must already possess a Commercial Driver's License (CDL). You'll need to pass a written knowledge test on handling large trucks with more than one trailer. Study the Mississippi CDL handbook, especially the section on doubles and triples. After passing the test, the endorsement will be added to your CDL.

To obtain a CDL Doubles/Triples license, you must already have a Commercial Driver's License (CDL). You'll need to pass a written knowledge test focused on handling large trucks with multiple trailers. This includes understanding coupling and uncoupling, inspecting doubles and triples, and crucial driving skills. Preparation via the state's CDL manual is highly recommended before taking the test.

While Mississippi does not specifically require specialized training for a CDL Doubles/Triples endorsement, it is highly recommended. The endorsement test covers topics like coupling and uncoupling, inspecting doubles and triples, and pulling double/triple trailers. Studying the CDL handbook and gaining practical experience can significantly improve your chances of passing the test.

Yes, to obtain a CDL Doubles/Triples endorsement, you must pass a specific written knowledge test. This test covers topics such as coupling and uncoupling, inspecting doubles and triples, and important driving skills. It's important to study the CDL handbook, particularly the section on doubles and triples, before taking the test.

The CDL Doubles/Triples endorsement test is a written examination, so no specific driving maneuvers are required. However, the test does assess your understanding of key skills such as coupling and uncoupling trailers, inspecting doubles and triples, and managing the substantial driving differences that come with operating these larger vehicles.

No, it's not permissible. Operating double or triple trailers requires a valid CDL Doubles/Triples endorsement in Mississippi, as well as in all other states. This endorsement ensures that the driver has the necessary knowledge and skills to safely operate these larger, more complex vehicles. Driving without the appropriate endorsement can result in fines and penalties.

Yes, you can append the CDL Doubles/Triples endorsement to your existing Commercial Driver's License. You don't need to initiate a new application for a CDL. However, you will need to pass the Doubles/Triples endorsement knowledge test to add this endorsement to your current CDL.

Yes, there are limitations for drivers holding a CDL Doubles/Triples endorsement. While this endorsement allows you to operate double and triple trailers, it doesn't permit the operation of other commercial vehicles like buses or tank trucks. Also, federal regulations limit the total length of these combinations to 81 feet. All drivers must abide by these and all other relevant rules and regulations.

The maximum weight for a double/triple trailer in Mississippi, with a CDL Doubles/Triples endorsement, is 80,000 pounds. The maximum length for a double trailer is 81 feet. However, the specific weight and length can vary depending on the combination of trailers. It's crucial to comply with these limits to ensure safety and avoid penalties.

Yes, when driving double/triple trailers, drivers must follow specific safety guidelines, including maintaining a safe following distance, avoiding sudden stops or lane changes, and inspecting the coupling devices and cargo regularly. Additionally, drivers must adhere to federal and state regulations regarding hours of service, vehicle weight and length limits, and hazardous materials transport.