Control & OperationQuestion 82 of 120
Why should you check the trailer height and the position of the fifth wheel jaws visually after coupling, even after a successful tug test?
a.A high hitch can appear locked while the kingpin sits on top of the closed jaws, which can pull apart in traffic
b.Visual checks are only needed on flatbed trailers
c.The tug test only checks the electrical connection
d.The jaws cannot be seen from outside the vehicle
Explanation
A high hitch can leave the kingpin resting above the jaws so the coupling looks secure but is not, which is why the manual requires looking under the trailer with a flashlight. Visual checks apply to all trailer types, the tug test is a mechanical check, and the jaws are visible from beneath the coupling.
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