2-1. TRAILER CONTROLS AND INDICATORS (Models WPES-10 and H-9518-1) - cont.
Brake System. Refer to figure 2-3. The service brakes are air actuated and controlled by the
towing vehicle. When the two air hoses (5 and 6) from the trailer are connected to the towing
vehicle, the service brake system and the brake pedal on the towing vehicle automatically operate
the trailer brakes. Disconnecting the air hoses causes the service brakes to engage automatically,
which serve as parking brakes for the trailer. If the air supply from both the towing vehicle and
the trailer reservoir is lost, a compression spring immediately locks the trailer brakes. Notify unit
maintenance if the trailer brakes are locked and trailer must be moved.
The leveling jacks must be in the stowed position (horizontal position) when
towing or shipping the ROWPU by truck or rail.
Leveling Jacks. Refer to figure 2-3. Leveling jacks (4) are installed at each comer of the trailer
(7). The jacks are manually operated by hand cranks (2) stowed on the trailer. Turning the crank
counterclockwise retracts the jack; turning the crank clockwise extends the jack. The mount (3)
permits the jack to swivel up or down. A spring inside the mount locks the jack in the vertical or
horizontal position. In the vertical and locked position, the jacks are used to level the trailer by
raising or lowering the trailer comers. When rotated to the horizontal position, the jacks are
stowed. The front jacks, when locked in the vertical position, can also be used to assist in
uncoupling the trailer from the towing vehicle.
Snare Wheel and Tire Carrier. Refer to figure 2-3. The spare wheel and tire carrier (9) is a
manually operated, cable-driven winch mounted under the rear of the trailer (7). The carrier is
operated by connecting the hand crank (2) to the carrier ratchet (1). Two (2) wheel lug nuts
secure the spare tire (8) to the carrier. The vehicles lug wrench is used for removing the lug nuts.
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