CDL Combination Vehicle Practice Test with Verified Answers | Latest 2025/2026 Update.

CDL Combination Vehicle Practice Test with
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Verified Answers | Latest 2025/2026 Update. i,- i,- i,- i,- i,-




You are driving a combination vehicle when the trailer breaks
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away, pulling apart both air lines. You would expect the trailer
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brakes to come on and ...i,- i,- i,- i,- i,- i,-




1. the tractor to lose all air pressure
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2. the tractor protection valve to close
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3. the trailer supply valve to stay open
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valve to close
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When you drive a set of doubles, which shut-off valve must be
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closed in the last trailer?
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1. Middle section
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2. front section
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3. back section
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The fifth wheel locking lever is not locked after the jaws close
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around the kingpin. This means that...
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1. the parking lock is off and you may drive away
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2. the trailer will not swivel on the fifth wheel
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, 3. the coupling is not right and should be fixed before you drive
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the coupled unit
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before you drive the coupled unit
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What gear should the tractor engine be in after you uncouple the
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trailer and are inspecting the trailer?
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1. neutral
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2. low reverse
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3. high reverse
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A tractor with a(n) ________ trailer requires the shortest amount of
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stopping distance . i,- i,- i,-




1. empty
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2. fully loaded
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3. lightly loaded
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The air leakage rate for a combination vehicle ( engine off, brakes
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on) should not be more than _____ psi per minute .
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1. 4
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2. 6
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3. 2
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