BC Transit – Air Brake Course

Completing the Coupling Procedure (Step 5)
The air lines have been connected. (red: supply/delivery; green: service/control)
The blue line is the electrical connection supplying power for the trailer lights and
turn signals.
The operator has opened the trailer supply valve and the trailer reservoir has been
filled with system air.
The operator now closes the trailer supply valve which “dynamites” (full on) the
trailer brakes.
The operator may now select a reverse gear and slowly back under the trailer until
the king pin locks securely into the
jaws of the fifth wheel.
With the landing gear of the trailer
still supporting the front of the
trailer and the trailer brakes still
dynamited, a tug test is performed to
make sure the jaws of the fifth wheel
locked around the king pin of the
trailer.
The unit is now ready for it’s pretrip
inspection.
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