Komatsu HM400-1, Manual

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MAINTENANCE
SERVICE PROCEDURE
CLEAN INSIDE OF COOLING SYSTEM
WARNING
Immediately after the engine is stopped, the engine coolant is hot and the pressure inside the radiator is high. Removing the
cap and draining the water under this condition could cause burns. Allow the engine to cool down, then turn the cap slowly
to release the pressure.
Start the engine and flush the system. When standing up or leaving the operator's seat, set the shift lever to the N position and
set the parking brake switch to the PARKING position.
For details of starting the engine, see "OPERATIONS, CHECKS BEFORE STARTING (PAGE 3-80)" and "STARTING ENGINE
(PAGE 3-81)" in the OPERATION section of the Operation and Maintenance Manual.
When the undercover is removed, there is danger of touching the fan.
Never go to the front of the machine when the engine is running.
Stop the machine on level ground when cleaning or changing the coolant.
Clean the inside of the cooling system, change the coolant and replace the corrosion resistor according to the table
below.
Kind of coolant
Cleaning inside of cooling system
and changing coolant
Replacing corrosion resistor
Permanent type antifreeze
(All season type)
Every year (autumn) or
every 2000 hours,
whichever comes first
Every 1000 hours and when
cleaning the inside of the
cooling system and
when changing coolant
Non permanent type antifreeze
containing ethylene glycol
(winter, one season type)
Every 6 months (spring, autume)
(Drain antifreeze in spring,
add antifreeze in autumn)
When no using antifreeze
Every 6 months or
every 1000 hours,
whichever come first
Use a permanent type of antifreeze.
If, for some reason, it is impossible to use permanent type antifreeze, use an antifreeze containing ethylene glycol.
The ratio of antifreeze to water depends on the ambient temperature, but to obtain the corrosion resistance effect,
a minimum ratio of 30% by volume is necessary.
When deciding the ratio of antifreeze to water, check the lowest temperature in the past, and decide from the mixing
rate table given below.
It is actually better to estimate a temperature about 10
°
C (18
°
F) lower when deciding the mixing rate.
Mixing rate of water and antifreeze
Min. atmospheric
temperature
°
C Above -10 -15 -20 -25 -30
°
F Above 14 5 -4 -13 -22
Amount of antifreeze
Liters 26.4 30.8 35.2 39.6 44
US gal 6.97 8.14 9.30 10.46 11.63
Amount of water
Liters 61.6 57.2 52.8 48.4 44
US gal 16.28 15.11 13.95 12.79 11.62
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