CDL Vehicle Combination Practice Test

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Prepare for the CDL Vehicle Combination Test. Access multiple choice questions, detailed answers, and hints to guide your study. Ace the exam with confidence!

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What is the consequence of cross-connecting the two air lines?

You will not have air going to the trailer brakes
You will lose power steering
The engine will stall
The truck will lose traction

The correct answer is: You will not have air going to the trailer brakes

Cross-connecting the two air lines means that the supply lines for the trailer's air brakes are improperly connected, causing a lack of air pressure in the system designed to operate the trailer brakes. Normally, one line delivers air to the trailer's braking system, while the other serves different functions, such as operating the emergency brakes. When these lines are crossed, it disrupts the proper flow of air, leading to an inability to pressurize the trailer brakes effectively. As a result, if there is no air going to the trailer brakes, it significantly diminishes the truck's ability to stop safely and efficiently when towing a trailer. This situation can lead to serious safety issues, such as increased stopping distances or the inability to stop entirely, which is critical in maintaining control over the vehicle and ensuring the safety of both the driver and other road users.