TM 5-3805-280-10
Operating the Engine
COLD WEATHER WARM-UP
5. Swing upperstructure so boom is perpendicular to
CAUTION: Prevent possible injury from
tracks.
unexpected machine movement. If hydraulic
oil is cold, hydraulic functions move slowly.
DO NOT attempt normal machine operation
CAUTION: Prevent possible injury from
until hydraulic functions move at
machine sliding backwards. Keep angle
between boom and arm 90--110.
close-to-normal cycle times.
In extremely cold conditions, an extended warm-up
6. Keeping the angle between boom and arm 90--
110, fully actuate bucket close function (cylinder
period will be necessary. Under such conditions, the
radiator and oil cooler should be covered to maintain
extend) and lower bucket to raise track off ground.
correct operating temperature.
IMPORTANT: Holding function actuated for more
Avoid sudden operation of all functions until the engine
than 10 seconds can cause damage
and hydraulic oil are thoroughly warm.
from hot spots in the control valve.
1. Run engine at 1/2 speed for 5 minutes. Do not run
7. While rotating raised track in forward direction,
at fast or slow idle.
actuate bucket curl function (cylinder extend) for 10
seconds and release for 5 seconds for a period of
2-1/2 minutes.
CAUTION: Prevent possible injury from
unexpected machine movement. Clear the
8. Repeat procedure with track rotating in reverse
area of all persons before running your
direction.
machine through the warm-up procedure. If
machine is inside a building, warm the
9. Lower machine to ground.
propel circuit first and move the machine to
a clear area outside. Cold oil will cause
10. Repeat steps 5--9 on opposite track.
machine functions to respond slowly.
11. Operate all hydraulic functions to distribute warm
2. Exercise propel and swing functions slowly, initially
oil in all cylinders, motors, and lines.
moving only short distances.
12. If hydraulic functions still move slowly, repeat
3. Operate boom, arm, and bucket functions by
steps 6 and 7.
moving cylinders a short distance each direction for
the first time.
4. Continue cycling cylinders by increasing the travel
each cycle until full stroke is obtained.
TX,25,DH5504 1921JUN951/1
5-10
