Air Brakes #2
Air Brakes Endorsement Test | Mississippi 2026 #2 Page 4 of 4
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 2026, 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.
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19 . Some air brake systems use alcohol:
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.
20 . Brakes can get out of adjustment quickly, especially:
Brakes are particularly prone to getting out of adjustment if they are hot. Be sure to routinely check the adjustment of your brakes. For a vehicle to be safely controlled, all brakes must be properly functioning and adjusted.
21 . What should happen if the air pressure in the air brake system tanks falls below 60 psi?
The vehicle should stop.
On vehicles with air brakes, a low air pressure warning signal will come on if the pressure in the air tanks falls below 60 psi. On large buses, the signal may activate at 80 to 85 psi.
22 . If the low pressure warning light comes on while you are driving:
You should stay at least 100 feet away from other vehicles.
When driving a vehicle with air brakes, if the low air pressure warning light comes on, it is important for you to stop and safely park your vehicle as soon as possible. There may be a leak in the system. Controlled braking will remain possible only as long as there is enough air left in the tanks.
23 . A slack adjuster should move no more than ____ from where it is attached to the push rod.
Before a trip, you should check each slack adjuster after parking, setting wheel chocks, and disengaging the parking brake. Pull the slack adjusters to make sure that 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.
24 . To use the stab braking method, you should:
Apply the emergency brake until the vehicle starts to slow.
The stab braking method for emergency stops involves fully applying the brakes until they lock up. The brakes are then released until the wheels start rolling, and then the process is repeated.
25 . When traveling down a steep downgrade, the best way to use your brakes is to:
Apply consistent pressure to the brake pedal all the way down the hill.
On a long or steep downgrade, brakes should only be used to supplement the braking effect of the engine. Apply the brakes just enough to feel a definite slowing down, then release them once you are about 5 mph below your target "safe" speed. Once your vehicle reaches its safe speed again, repeat this process.
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2026 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.
