CDL Vehicle Combination Practice Test

Disable ads (and more) with a membership for a one time $2.99 payment

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

Practice this question and more.

What is the function of a king pin in a combination vehicle?

It connects the air lines
It locks the trailer to the tractor on the fifth wheel
It supports the weight of the trailer
It controls the braking system

The correct answer is: It locks the trailer to the tractor on the fifth wheel

The king pin plays a crucial role in the coupling mechanism of a combination vehicle, specifically by locking the trailer to the tractor at the fifth wheel. This connection is essential for secure coupling, allowing for the safe transport of loads. The king pin is a sturdy, pin-like component that fits into a slot in the fifth wheel, which is mounted on the tractor. This arrangement ensures that the trailer is firmly attached during travel, preventing it from becoming uncoupled and enhancing overall safety on the road. While there are other components in a combination vehicle that manage air lines, support weight, or control braking systems, the primary function of the king pin specifically pertains to its role in securing the trailer to the tractor. Understanding this function is vital for drivers to ensure that they can safely couple and uncouple their trailers during their operations.