freightliner Cargo Manual page 116

Fifth Wheels
8. After lockup is completed, connect the tractor-to-
trailer air system lines and the electrical cable to
the trailer. Take care to prevent dirt or foreign mate-
rial from entering the air system lines.
9. Charge the air brake system with air. Make sure
that the air connections do not leak.
10. With the trailer wheels chocked and the brakes set,
check for clearance between the kingpin and the
fifth wheel jaws by moving the tractor forward and
backward against the locked kingpin. There should
be no slack between the tractor and the trailer. If
slack is present, uncouple the trailer.
For adjustment instructions, refer to the applicable
manufacturer's service information.
WARNING
Eliminate slack between the trailer and the tractor.
Incorrect fifth wheel adjustment could cause the
trailer to disconnect, possibly resulting in serious
personal injury or death.
11. Retract the trailer landing gear, and secure the
ratchet handle.
12. Remove the chocks from the trailer tires.
11.9
13. The load distribution on the front steering axle and
rear drive axle(s) will have a direct effect on the
steering control of the vehicle.
Determine the front and rear axle weights by weigh-
ing the vehicle on scales designed for this purpose.
The maximum axle weight ratings are given on the
Federal Motor Vehicle Safety Standard (FMVSS)
label or Canadian Motor Vehicle Safety Standard
(CMVSS) label attached to the left rear door post of
the tractor. The desired load on the axle is no less
than 80 percent of the maximum axle weight rating,
but in no case should the axle load exceed the
maximum axle weight rating given on the FMVSS
or CMVSS label.
WARNING
Do not overload any tractor axle by improperly
loading the trailer. This could cause erratic steering
and loss of vehicle control, possibly resulting in
serious personal injury or death.
Unlocking the Fifth Wheel Lock Mechanism
1. Apply the tractor parking brakes.
2. Pull the trailer air supply valve to cut off the air sup-
ply to the trailer.