Figure 2-1. Connections
Used in Coupling Semitrailer
to Towing Vehicle.
Proper operation of semitrailer primary brake
system is essential for safe operation of ve-
hicle. Functional system check is necessary
before putting trailer into service. Semitrailer
parking brakes are provided to maintain brak-
ing and holding requirements whether semi-
trailer is fully loaded or empty. The system will
automatically apply the parking brakes when
air pressure in primary reservoir falls below
specified pressure. Proper operation of this
system must be maintained.
c. Close the drain valves on front and rear reservoir
tanks (fig. 2-2). Open the shut-off valves on the air lines of
the towing vehicle.
d. Plug the intervehicular cable into receptacle
on semitrailer. Operate lights
vehicle to make sure that all semitrailer lights are working
e. Release the landing gear operating crank
(fig. 2-3) from its clip and engage the crank
on its shaft.
When there is no load, pull out on the crankshaft to
engage high-speed gears for fast raising or lowering of the
telescoping legs. When greater power is needed, push in
on the operating shaft to engage the low-speed gears to
lower or raise the legs. Rotate the crank clockwise to raise
the landing gear legs. Replace crank in clip.