Glad hands are usually connecting which of these?
Answer: A
Service and emergency air lines from the vehicle to the trailer.
Glad hands are couplers that use a rubber seal to prevent air from escaping when connecting the service and emergency air line between the truck/tractor and the trailer.
All choices
- AService and emergency air lines from the vehicle to the trailer.
- BElectric lines from the tractor to trailer.
- CKingpin from the trailer to the locking jaws of the fifth wheel.
Why the other answers are wrong
B. Electric lines from the tractor to trailer.
Electric lines are connected by electrical connectors, not glad hands, which are specifically for air lines.
C. Kingpin from the trailer to the locking jaws of the fifth wheel.
The kingpin connects to the fifth wheel locking jaws, not via glad hands which are air line couplers.
CDL Combination Vehicles Test Info
Questions on Exam
20
Passing Score
80%
Time Limit
Typically 30 minutes; varies by testing location
The Combination Vehicles test content is federally standardized, so this question applies in every state. Age limits, fees, and testing procedures do vary — check your state's CDL requirements.
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More CDL Combination Vehicles Practice Questions
- After connecting the air lines but before backing under the trailer you should:
- The crack-the-whip effect is related to:
- Sudden turns or aggressive braking will have the greatest effect on which trailer?
- Which task is NOT performed during the tractor protection valve test?
- What is the purpose of the trailer air supply control?