Daf LF.book - Peterbilt Motors Company

Coupling and Uncoupling
D000503
CONNECTING UP THE BRAKE LINES OF A TRAILER
The vehicle has automatic coupling heads which are used to connect up the air
pipes.
Connect the air pipes with these connectors. These coupling heads have safety
lugs which make it impossible to connect up the air pipes incorrectly. The coupling
heads on the trailer vehicle must of course have corresponding safety lugs.
Should a mistake nonetheless be made when connecting up the air lines the air
brakes on the trailer vehicle will consequently not be released.
}
However, an incorrectly connected trailer vehicle with empty air
reservoirs will not be braked automatically and this makes it
possible to drive away with an unbraked trailer. This can lead to
very dangerous situations!
When the red coupling head is properly connected, the brake system of the trailer
vehicle will slowly be filled and you will be able to hear this quite clearly. At the same
time there will be a marked drop in pressure in the air reservoirs of the tractor.
156