CDL Combination Vehicles Practice Test Results

Question 1
90% answer correctly
How would a driver supply air to trailer air tanks?
Activate the air generator
Pull out the trailer air supply valve
Activate the service line
Push in the trailer air supply valve
Question 2
92% answer correctly
On a combination vehicle what color is the emergency air line?
Red
Black
Yellow
White
Question 3
53% answer correctly
What function does the service line perform?
Distributes air throughout the cab and to each of the trailers
Carries air controlled by the footbrake or trailer handbrake
Marks the maximum refill point for air tanks
Supplies air to the footbrake and trailer handbrake