CHAPTER 5
OPERATING INSTRUCTIONS
Section I. OPERATING PROCEDURES
(5) Engine oil pressure gage. This gage
5-1.
General
indicates the oil pressure in the carrier engine. Normal
Refer to paragraph 2-1 and para 2-2 for equipment
oil pressure is 40 psi, with an acceptable variation of 5
inspection and servicing procedures and for installation
psi above or below.
or setting up instructions.
(6) Left turn directional lamp. This lamp will
5-2.
Controls and Instruments
"blink" when the directional turn lever is pulled downward
a. General. The carrier operating controls and
to signal a left turn.
instruments are shown in figure 5-1. A description of
(7) Speedometer/ odometer. This instrument
each control is given below. The controls are listed in
indicates the carrier speed in miles per hour and
the order of their appearance on figure 5-1.
accumulated total carrier mileage.
Note. The operator must study the information
(8) High beam indicator.
This lamp is
in this section. and be thoroughly familiar with
illuminated when the carrier headlights are on high
location and function of each control.
before
beam.
attempting to operate the machine.
indicates engine speed in hundreds of revolutions per
b. Controls.
minute and accumulated engine operating time in hours.
(1) Master light switch.
The master light
(10) Right turn directional lamp. This lamp will
control switch (fig. 5-1) has three handles.
"blink" when the directional turn lever is pushed upward
They are:
to signal a right turn.
(a) Lock lever A. This lever prevents
(11) Air pressure gage. This gage indicates air
the outside lamp selector lever (lever B) from moving.
pressure in the air brake system in pounds per square
except into the blackout position.
This prevents
inch (psi).
accidental actuation of lights under blackout conditions.
(12) Park abort control. This control is used to
Move this lever upward and hold to allow lever B to be
drain down air pressure in the air brake system and
turned to any position other than blackout.
maintain the brake shoes out of contact with the brake
(b) Outside lamp selector switch B.
drums.
The desired combination of lights may be selected by the
(13) Engine throttle control. Pull out on this
operator by lifting lock lever A and turning switch B. This
control to increase engine idle speed. Push in on the
lever has five positions. They are:
control to decrease engine speed.
(1) Blackout drive
(14) Reservoir drain valve. Depress and hold
(2) Blackout marker
this valve depressed to drain all air pressure form the air
(3) Off
pressure from the air brake reservoir.
(4) Stop lights
(15) Tractor protection valve. This valve is
(5) Service drive
used only when towing another vehicle, and should not
(c) Panel light selector switch C. This
be pushed in when another vehicle is not being towed.
switch selects the type of panel lighting in four positions,
In normal towing service, push the valve in. In an
as follows:
emergency, if it becomes necessary to apply the brakes
(1) Park
of the towed vehicle, pull this valve out.
(2) Off
(16) Emergency-release park lever. This leer
(3) Dim
selects the basic mode of operation of the air brake
(4) Bright
system. Place the leer in the RELEASED position for
(2) Cab dome light switch.
This switch
normal operation. Place the lever in the EMERGENCY
controls the cab dome lights.
position for short term parking. Place the lever in the
(3) Oil temperature warning light. This light
PARK position for long term parking.
will turn on when oil pressure is below the safe
(17) Interaxle differential lockout. When very
maximum.
(4) Water temperature warning light. This
light will turn on when water temperature is above the
safe maximum.
5-1
