CDL Combination Test Questions with Correct Answers 2026 | Complete Commercial Driver Exam Study Guide

CDLCOMBINATIONTESTQUESTIONS b b b




WITH CORRECT ANSWERS 2026 b b b b




If you cross connect the two air lines the following will result - CORRECT ANSWER-
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You will not have air going to the trailer brakes
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You have coupled with a semi-
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trailer. In what position should you put the front trailer supports before driving away? -
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CORRECT ANSWER-Fully raised with the crank handle secured in its bracket
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Th trailer air supply control: - CORRECT ANSWER-Is a red, eight sided knob
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A device which connects the service and emergency air lines from the truck to the trailer is
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called.. - CORRECT ANSWER-Glad hands
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If one of the glad hands on your blue air line is missing a seal: - CORRECT
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bANSWER- You might end up with a service line air leak b b b b b b b b b b




In order to supply air to the trailer, you must first: - CORRECT ANSWER-
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Stop engine so you can hear the brakes
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The hand valve should be used: - CORRECT ANSWER-To test the trailer brakes
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The air leakage rate for a combination vehicle (engine off, brakes on) should not be more t
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han
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When should you use the hand valve to park a combination vehicle? - CORRECT ANSWER-
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Never
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, When you get ready to back under the semi-trailer you should line up - CORRECT ANSWER-
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Directly in front of the trailer
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If the service air line comes apart while you are driving a combination vehicle but the emer
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gency line stays together, what will happen right away - CORRECT ANSWER-
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Nothing is likely to happen until you try to apply the brakes
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When uncoupling, if you park the trailer at an angle... - CORRECT ANSWER-
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You could do damage to the landing gear
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Which of these statements is true? - CORRECT ANSWER-
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"Bobtail" tractors can take longer to stop than a combination vehicle loaded to the maximu
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m gross weight
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In normal driving, some drivers use the hand valve before applying the brake pedal to prev
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ent a jackknife. Which of these statements is true? - CORRECT ANSWER-
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It should not be done
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When you inspect the coupling, check to ensure that: - CORRECT ANSWER-
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There's a little slack in the air lines
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When backing under a tractor under a trailer you should expect: - CORRECT ANSWER-
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Trailer will be lifted slightly when the tractor back under it
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A king pin is: - CORRECT ANSWER-
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A pin which locks the trailer to the tractor on the fifth wheel
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The safety catch for the fifth wheel locking level must be
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lete. - CORRECT ANSWER-Over the locking lever
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