Questions appearing on this CDL practice test:
The air leakage rate for a combination vehicle (engine off, brakes on) should not be more than ____ PSI per minute.
Why should you lock the tractor glad hands to each other or to the storage bracket when you are not towing a trailer?
You are driving a combination vehicle when the trailer breaks away, pulling apart both air lines. You would expect the trailer brakes to come on and:
The hand valve should be used:
Combination vehicles take longer to stop when they are empty than when they are fully loaded, because
To uncouple a loaded trailer, after the landing gear has made firm contact with the ground, you should
The tractor protection valve is designed to close automatically when the air pressure falls into the pressure range specified by the manufacturer, typically
If the brakes did not release when you pushed the trailer air supply valve, you should
In general, the higher your truck's center of gravity, the
When you test the tractor protection valve, the red air supply control knob should go into the ________ position.
When coupling, the proper position of the fifth wheel is
The front trailer supports are up, and the trailer is resting on the tractor, make sure:
You are coupling a tractor to a semi-trailer and have backed up but are not under it. What should you hook up before backing under?
Before you back under a trailer, make sure the:
On a double or triple vehicle, which wheels off-track the most?
Which statement best illustrates the "crack-the-whip" effect?
To test the tractor protection valve, charge the trailer air brake system, turn off the engine, and
Which of these vehicles off-tracks the most?
Almost half of all truck driver deaths are the result of
At night, when a vehicle is carrying a load that extends four feet or more beyond the rear of the body, there must be _______ at the extreme end of the load.