CDL Combination Vehicles Practice Test Results

Question 1
87% answer correctly
In which of the following circumstances should the valve hand be used to park a combination vehicle?
Never
When parked on a grade
When parking for less than 10 minutes
When unloading
Question 2
89% answer correctly
When is the proper time to use the trailer handbrake to straighten out a trailer that`s jackknifing?
When you start to recover from the jackknife
As soon as you start to jackknife
In the middle of the jackknife
Never
Question 3
63% answer correctly
Suppose a trailer separates from the tractor and pulls apart the air lines. The trailer brakes would apply causing which of the following to occur?
The tractor would lose air pressure through the parted air lines
The tractor brakes would lock up
The tractor brakes would apply
There would be no impact to the tractor brakes