Section III. OPERATION UNDER UNUSUAL CONDITIONS
f. Starting.
2-23. Operation in Extreme Cold (Below
(1 ) At very low temperatures, provide heat in
0 F or --18 C)
the cab for as long as possible before attempting to start
a. General. Operation in extreme cold presents
the engine.
special problems due to the increased brittleness of
Warning: Do not use an open flame as the
metallic and rubber parts, the danger of freezing, and the
source of heat.
increased difficulty of keeping parts lubricated
(2) Crank the engine with the ignition off to
adequately.
Warning: Personnel should use care to keep
(3) Lift the choke knob to provide the richest
from spilling fuel, coolant, or other liquids upon
fuel mixture possible. Advance the throttle control to its
themselves. Exposed parts of the body should not
middle position.
come into contact with metal during cold weather, as
(4) Turn on the ignition switch and start the
serious and painful injury may result.
engine. If the engine does not start, determine whether
b. Lubrication.
the fuel line is frozen.
(1) Refer to current LO for special lubricants
g. Warmup. Cover part of the air passages through
to be used at various temperatures.
the radiator, to aid warmup and to maintain engine
(2) When using OES oil in the crankcase, the
running temperature. During warmup only, the entire
oil level must be checked frequently, as oil consumption
radiator may be covered.
may increase.
h. Stopping. Set all dippers. buckets. or loads on
c. Cooling System.
blocks to keep them from freezing to the ground, leaving
(1) Drain and flush the cooling system, to
just enough tension in the cables to keep them taut. Set
ensure proper circulation of coolant throughout the
all drum pawls. and release the clutches and brakes.
radiator core. Clean the radiator cooling fins,
Turn off the engine ignition. Close all cab openings
particularly the air passages through the core.
securely.
(2) Inspect the cooling system for leaks.
i. Operation on Snow or Ice. Take all necessary
Replace worn or damaged hose connections. Lighten
precautions to insure a firm footing for the truck crane.
the hose clamps.
Extend the outriggers (para 2-21) using blocking under
(3) Fill the cooling system with the proper
the jackfloats to obtain firm footing.
amount and mixture of antifreeze. Refer to TB750
2-24. Operation in Extreme Heat
(4) After filling the cooling system. run the
a. General. Operation in extreme heat presents
engine to mix the antifreeze solution thoroughly.
special problems due to the difficulty in keeping the
d. Batteries.
engine from overheating.
(1) Keep the batteries fully charged at all
b. Lubrication.
times. The electrolyte in a discharged battery will freeze
(1) Refer to current L() for lubricants to be
.at a higher temperature than that in a fully charged
used.
battery.
(2) Make certain that the engine crankcase oil
(2) If the batteries require water, add only
is at the proper level.
An inadequate supply of
before or during operation. or charge the batteries from
crankcase oil will prevent proper dissipation of heat from
an outside source. Charging the batteries will mix the
the engine.
water and the electrolyte. and prevent them from
c. Cooling System.
freezing.
(1) Drain and flush the cooling system. to
(3) Keep the battery terminal connections
insure proper circulation of coolant throughout the
clean and free from snow or ice accumulations, which
radiator core. Clean the radiator cooling fins, particularly
may short circuit the batteries externally, causing them to
the air passages through the core. of insects, leaves.
discharge.
dirt, and other foreign material that will restrict air flow.
(4) In extremely low temperatures. remove
(2) Inspect the cooling. system for leaks.
the batteries and place them in a heated shelter when
Replace worn or damaged hose connections. Tighten
not in use. The current output from a warm battery; will
the hose clamps.
be higher than that from a cold battery.
(3) Keep the water pump fan belt adjusted
c. Fuel System. Keep the fuel tank as full as
properly.
possible at all times to minimize condensation. If the
(4) If the engine becomes overheated from
presence of water is noted in the fuel supply. drain the
lack of coolant, let the engine run at a fast idle and add
tank and refill it with clean fuel. Refer to figure 3-2 and :
coolant slowly.
(5) If the engine overheats after refilling the
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