Coupling & UncouplingQuestion 6 of 60
After the tug test, why should you go under the trailer and look into the back of the fifth wheel?
a.To check the color of the kingpin
b.To confirm the fifth wheel jaws have closed around the shank of the kingpin
c.To measure the height of the landing gear
d.To grease the fifth wheel plate
Explanation
You should go under the trailer with a flashlight and look at the back of the fifth wheel to confirm the locking jaws have closed completely around the shank, not the head, of the kingpin. This visual check catches a false coupling that the tug test alone might miss. A gap means the coupling is not safe.
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Related questions on this topic
- Before backing under a trailer, the fifth wheel should be tilted how?
- When connecting the glad hands, what must you check to avoid a dangerous coupling mistake?
- After the kingpin has locked into the fifth wheel, how should you test that the coupling is secure?
- When should the locking jaws be closed around the kingpin?
- After the trailer is securely coupled and supported by the tractor, what should you do with the landing gear?
- Before supplying air to the trailer, why should you check the trailer brakes are set?
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