Air Brakes #2
Air Brakes Endorsement Test | Tennessee 2025 #2 Page 4 of 4
Train for FREE online with our Tennessee 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 TN 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.
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19 . Dollies equipped with ABS are required to have malfunction lamps located where?
On the top
A dolly equipped with an Anti-Lock Braking System (ABS) is required to have a yellow malfunction lamp located on its left side.
20 . The air pressure in a dual air brake system should build from 85 to 100 psi within:
45 seconds.
When inspecting a vehicle with a dual air brake system, you should wait for air pressure to build from 85 to 100 psi in both the primary and secondary systems. This should take about 45 seconds.
21 . Why do you need to drain air tanks regularly?
To remove bad air from the tanks
Compressed air in an air brake system usually contains a certain amount of water and compressor oil. The water and oil can damage the brakes if left to accumulate in the system. Tanks must be drained regularly to remove this build-up.
22 . Brake linings should be:
Brake linings should not be loose or soaked with oil or grease. They shouldn't be dangerously thin.
23 . Front brake limiting valves were intended to:
Remove uncertainty when applying the brakes.
Some older vehicles with air brakes have front brake limiting valves. These valves were intended to reduce the risk of front wheels skidding. However, research has shown that such devices are unnecessary, so they should be left in the "normal" position.
24 . Air tank drains:
Must remain open while driving.
In an air brake system, the air tanks are equipped with drains that allow water and compressor oil to be removed from the system. If allowed to build up, water and compressor oil can damage an air brake system.
25 . The ____ between an air compressor and reservoir tank prevents air from escaping if the air compressor has a leak.
A one-way check valve is required to be between an air compressor and the first main reservoir. This valve prevents air from escaping the system if the air compressor develops a leak.
2025 Tennessee | Frequently Asked Questions
To secure a CDL Doubles/Triples endorsement in Tennessee, you must already have a Commercial Driver’s License (CDL). You will need to pass the Doubles/Triples Knowledge test. Study the relevant section in the TN CDL manual before taking the test. Once you pass, the endorsement will be added to your CDL.
To obtain a CDL Doubles/Triples license, you must have a valid Commercial Driver’s License (CDL). You'll also need to pass the Doubles/Triples Knowledge test. This test covers the specific skills and knowledge needed to safely operate such vehicles. Studying the relevant sections of your state's CDL manual will help you prepare for this test.
While you don't necessarily need specialized experience or training to get a CDL Doubles/Triples endorsement, it's highly recommended. You must pass the Doubles/Triples Knowledge test, so studying the relevant sections of your state's CDL manual is crucial. Some choose to attend a CDL training school for hands-on experience before taking the test.
Yes, to acquire a CDL Doubles/Triples endorsement, you must pass the Doubles/Triples Knowledge test. This test evaluates your knowledge of safely operating double and triple trailers, coupling and uncoupling, inspecting doubles and triples, and more. It's crucial to study the relevant sections of your state's CDL manual thoroughly before taking the test.
The CDL Doubles/Triples endorsement test is primarily a written exam, focusing on your knowledge rather than specific driving maneuvers. It covers areas such as coupling and uncoupling, inspecting doubles and triples, and the specifics of managing these larger vehicles. However, it's beneficial to practice driving these larger vehicles for real-world application of these principles.
No, it is not permissible to operate double/triple trailers without a valid CDL Doubles/Triples endorsement in Tennessee. The state requires drivers to obtain this endorsement to ensure they have the necessary knowledge and skills to safely operate such vehicles. Violating this requirement can result in penalties and potential suspension of driving privileges.
You can add the CDL Doubles/Triples endorsement to your existing commercial driver's license. You don't need to initiate a new application for a separate license. However, you must pass the Doubles/Triples Knowledge test to get this endorsement. It's important to check with your local DMV for specific state requirements and procedures.
Yes, there are limitations. A CDL Doubles/Triples endorsement only permits you to drive vehicles with more than one trailer. However, it doesn't allow you to operate other special vehicle types like buses or tank vehicles unless you have the specific endorsements for those. Also, all federal and state regulations regarding hours of service, vehicle maintenance, and load securement must still be followed.
In Tennessee, the maximum legal weight for a vehicle including double/triple trailers is 80,000 pounds. The maximum length for each semi-trailer is 28 feet 6 inches, and for each full trailer it's 28 feet. However, these restrictions can vary depending on road types and specific routes. Always check local regulations to ensure compliance.
Yes, drivers with a CDL Doubles/Triples endorsement must adhere to specific safety regulations. These include performing routine vehicle inspections, following appropriate coupling and uncoupling procedures, and maintaining safe following distances. They must also understand the high rollover risk associated with these vehicles and the effects of speed and curves on stability. Compliance with these guidelines helps ensure road safety.