CDL Combination Vehicles Practice Test Results

Question 1
82% answer correctly
Before backing under a trailer that you`ve just hooked to your tractor you should:
Make sure the fifth wheel has been removed
Hook up the service and emergency lines
Hook up the electrical lines
Ground the trailer
Question 2
75% answer correctly
The locking jaws should close around the __________ of the kingpin.
Top
Neck
Shank
Base
Question 3
75% answer correctly
You`re hooking a tractor to a trailer. After connecting the air lines and before backing under the trailer you should:
Pull forward to test the strength of the air line connection
Activate air supply to the trailerarray(s) then lock the trailer brakes
Be sure not to activate air supply to the trailerarray(s) to prevent damage to the air delivery system
Activate air supply to the trailerarray(s) and leave the trailer brakes unlocked