freightliner 108SD, Driver Manual

Page: 131 / 192

brakes are set. See Chapter 5 in this manual for
operation of the dash-mounted brake controls.
NOTICE
Attempting to couple at the wrong height may
cause improper coupling, which could result in
damage to the fifth wheel or kingpin.
7. Adjust the trailer height (if required).
For a standard fifth wheel plate , the trailer
should contact the fifth wheel approximately 4 to
8 inches (10 to 20 cm) behind the pivot. See
Fig. 17.4 .
For a low-lube fifth wheel plate , the fifth wheel
must slide freely under the trailer, and the trailer
should contact the fifth wheel at the pivot. See
Fig. 17.5 .
8. Back the vehicle under the trailer.
On a standard fifth wheel, the fifth wheel must lift
the trailer.
On a low-lube fifth wheel, do not lift the trailer as
this may damage the fifth wheel plate.
9. After sliding under the trailer, STOP to prevent
from hitting the kingpin too hard, then resume
backing slowly until the fifth wheel locks.
10. Apply the vehicle parking brake.
WARNING
A visual inspection is required by law. Some im-
proper couplings can pass a pull test. Sound is
not reliable. Get out of the cab and look. Incor-
rect coupling could cause the trailer to discon-
nect, possibly resulting in serious personal injury
or death.
11. Perform a physical check for positive kingpin
lockup, ensuring that there is no gap between
the trailer and the fifth wheel. See
Fig. 17.6 .
12. Ensure that the release handle is in the locked
position adjacent to the casting. See Fig. 17.8 .
13. Release the vehicle parking brake and test for
kingpin lockup by slowly moving the vehicle for-
ward, pulling on the trailer against the chocks.
Fifth Wheel Uncoupling
Manual Uncoupling
1. Apply the vehicle and trailer parking brakes.
2. Chock the trailer rear wheels.
3. Lower the trailer landing gear until the weight is
removed from the fifth wheel.
4. Disconnect the tractor-to-trailer air system lines
and electrical cable. Plug the air lines to prevent
dirt or foreign material from entering the lines.
5.
Verify that both the yellow parking-brake and red
trailer air supply knobs are out, the vehicle and
trailer parking brakes are set, and that the trailer
is prepared for uncoupling.
6. Release the kingpin locking mechanism following
the instructions for each manufacturer lilsted
below.
6.1 Fontaine: Lift the safety latch and pull the
lock control handle to the unlocked posi-
tion. See
Fig. 17.2 .
6.2 Holland: In the locked position the safety
indicator swings freely over the operating
rod. See
Fig. 17.9 , View A.
To unlock the mechanism, manually rotate
the safety indicator toward the rear of the
fifth wheel. See
Fig. 17.9 , View B.
Pull the operating rod out. When the
upper operating rod shoulder is outside
the slot, raise the handle and place the
shoulder of the upper rod against the plate
casting, above the slot. See
Fig. 17.9 ,
View C.
09/10/2010 f311128
A
A. Lock held open by catch mechanism
Fig. 17.7, Jost Release Handle Unlocked
Fifth Wheels
17.4