TM 5-3805-281-24-1
Tests
HYDRAULIC SYSTEM WARM-UP PROCEDURE
SPECIFICATIONS
viscosity oil to minimize warm-up period. (See
50 5C (120 10F)
Hydraulic Oil in Fuels and Lubricants Group.)
Hydraulic Oil Temperature
1. Connect digital thermometer. Install temperature
SERVICE EQUIPMENT AND TOOLS
probe on hydraulic tank-to-pump inlet line. (See
JT05800 Digital Thermometer
JT05800 Digital Thermometer Installation in this
group.)
IMPORTANT: If the machine temperature is below
-18 degrees C (0F), start the engine
with the speed control in the idle
CAUTION: Avoid possible serious injury
position. If the unit has been
from machine movement during warm-up
prepared for arctic operation with
procedure. Clear the area of all bystanders
the MIL-L-46167 hydraulic oil, the
before doing the warm-up procedure.
suction strainer in the hydraulic tank
should also have been changed to
2. Clear the area of all bystanders to allow for
the coarser strainer for use in arctic
machine movement.
conditions. Failure to do this could
cause the hydraulic pump to cavitate
3. Start engine. Run engine at 1/2 speed for
which can cause pump failure.
approximately 5 minutes before operating any
Operate engine at idle speed for at
functions. Do not run engine at fast or slow idle.
least 10 minutes before increasing
the speed to half. Cover the radiator
4. Check that work mode is in Dig Mode and power
and oil cooler debris screens to
mode is in Standard Mode (no buttons pushed
restrict the air flow for faster
down, indicators off). Push auto-idle switch to turn
warmup.
off auto-idle function (auto-idle indicator off).
9025
Below -18C (0F) an extended warm-up period may
25
5. Slowly turn upperstructure so boom is to the side.
42
be necessary. Hydraulic function will move slowly and
lubrication of parts may not be adequate with cold oil.
CAUTION: Avoid possible serious injury
Do not attempt normal machine operation until
from machine sliding backwards. Keep angle
hydraulic functions move at or close to normal cycle
between boom and arm at 90--110
times.
6. Keeping the angle between boom and arm at 90--
Operate functions slowly and avoid sudden
110, lower boom to raise one track off the ground.
movements until engine and hydraulic oils are
thoroughly warmed. Operate a function by moving it a
7. Operate propel function for approximately 5 minute.
short distance in each direction. Continue operating
the function increasing the distance traveled in each
8. Once oil temperature is above -18C (0F), increase
cycle until full stroke is reached.
engine speed to fast idle.
For faster warm-up, restrict air flow through oil cooler
using cardboard or other similar material. Use correct
Continued on next page
TX,25,GG2232 1920NOV971/2
