What should you do immediately after locking the kingpin into the fifth wheel during coupling?
a.Raise the landing gear
b.Connect the air lines
c.Pull the tractor forward gently to test the coupling
d.Connect the electrical cord
Explanation
After the kingpin locks into the fifth wheel, you should pull the tractor forward gently to test that the fifth wheel has locked onto the kingpin properly. This tug test is critical to ensure a secure coupling.