freightliner Columbia Driver Manual page 135

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 instances should the
axle load exceed the maximum axle weight rat-
ing given on the FMVSS or CMVSS label.
WARNING
Do not overload any tractor axle by improperly
loading the trailer. This could cause erratic steer-
ing 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
supply to the trailer.
3. Chock the front and rear of the trailer tires to
prevent the trailer from moving.
WARNING
Do not use the trailer air supply for parking trail-
ers not equipped with spring parking brakes.
This applies the trailer service brakes only. As air
bleeds from the trailer brake system, brake appli-
cation is lost. This could allow the unattended
vehicle to roll away, possibly resulting in serious
personal injury or death.
4. Lower the trailer landing gear until the weight is
removed from the fifth wheel.
5. 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.
CAUTION
Before attempting to lock or unlock the fifth
wheel lock mechanism of a sliding type fifth
wheel, the slide release plungers must be in the
locked position. This prevents the sliding mem-
ber from moving rapidly to the far forward or
rearward position, which could damage the fifth
wheel or kingpin.
Fifth Wheels and Trailer Couplings
6. Release the kingpin locking mechanism by pull-
ing the kingpin lock control handle
the outward position.
7.
Slowly drive the tractor away from the trailer.
Fifth Wheel Slide Operation
1. Connect the trailer kingpin to the tractor fifth
wheel. For instructions, refer to Holland "Fifth
Wheel Locking Operation" in this chapter.
2. After positive lockup of the fifth wheel lock
mechanism has been accomplished, release the
sliding member using one of the following meth-
ods:
2.1
9/07/95
Fig. 10.6, Cab Control, Fifth Wheel Slide
2.2
3. Lower the trailer landing gear just enough to re-
move the weight from the tractor.
4. Pull the trailer air supply valve to cut off the air
supply to the trailer.
5. Chock the front and rear of the trailer tires to
prevent the trailer from moving.
For air-operated models, set the cab-
operated control switch
UNLOCK.
For manual release models, pull the re-
lease lever (Fig. 10.3) using a release
hook, or other suitable tool. Make sure
both slide plungers have released. See
Fig. 10.7. If the plungers haven't released
(haven't come out), lower the trailer land-
ing gear to relieve pressure on the
plungers.
(Fig. 10.1) to
(Fig. 10.6) to
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10.4