(2) Perform before-operation services (par. 45c).
(3) Fill the fuel tank with a good grade of gasoline. Fuel tank capacity is 42 gallons.
(4) The cooling system is filled with 60 percent anti-freeze and 40 percent water and is ready for operation.
(5) Add sulfuric acid and distilled water to all batteries. The level of electrolyte should be from 3/8-inch to 5/8-
inch above the top of the separators of each cell. Inspect battery connections (par. 45f).
(6) Perform all truck services as instructed in TM 9-819.
7. Used Equipment
The inspection and service of used equipment will be the same as that for new equipment (par. 6). However, the
equipment must be more carefully inspected before it is operated. Examine the entire unit for loose or damaged
connections-oil, water, electrical or air. Inspect for evidence of oil seepage and check gages for proper operation. Tighten
loose mounting bolts if necessary. Start the compressor (par. 30) and listen carefully for unusual sounds or noises. If an
unusual condition is indicated, stop the compressor immediately and report to proper authority.
Section II. CONTROLS AND INSTRUMENTS
8. General
This section describes, locates, illustrates, and furnishes the operator sufficient information about the various controls and
instruments for the proper operation of the materiel.
9. Unloader Pilot Valve
a. Location. The unloader pilot valve is located on the crankcase cover and is interconnected by tubing to the
compressor valve assembly, the slowdown assembly, and the air receiver.
b. Purpose. The unloader pilot valve is actuated automatically by the amount of air pressure in the air receiver.
When air pressure in the receiver drops to approximately 90 psi, the unloader pilot valve closes and cuts off the air
pressure to the intake valve unloaders to close the intake valves. When air receiver pressure reaches 100 psi, the
unloader pilot valve opens to allow air pressure to enter the intake valve unloaders and open the intake valves.
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