Clean Inside Of Cooling System - Komatsu D61EX-12 Operation And Maintenance Manual

MAINTENANCE

CLEAN INSIDE OF COOLING SYSTEM

Just after the engine is stopped, the cooling water is still hot and the internal pressure in the radiator
is still high. If the radiator cap is removed under this condition, you may scald yourself. Accordingly,
wait until the temperature lowers, then loosen the cap slowly to release the pressure.
Start the engine to clean the cooling system. When standing up from the operator's seat or leaving the
machine, set the safety lock lever and brake lock lever in the LOCK positions.
For the starting method of the engine, see "CHECK BEFORE STARTING ENGINE, ADJUST (PAGE 3-
38)" and "STARTING ENGINE (PAGE 3-54)" in OPERATION in the volume of operation.
Never go into under the machine body while the engine is running. It is very dangerous since the
machine may move suddenly.
Clean the inside of the cooling system, change the coolant and replace the corrosion resistor according to the
table below.
Kind of coolant
Permanent type antifreeze
(All season type)
Non permanent type antifreeze
containing ethylene glycol
(winter, one season type)
When not using antifreeze
Stop the machine on level ground when cleaning or changing the coolant.
Use a permanent type of antifreeze.
If, for some reason, it is impossible to use permanent type antifreeze, use an antifreeze containing ethylene glycol.
Super Coolant (AF-ACL) has an anti-corrosion effect as well as an antifreeze effect.
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 mix-
ing rate table given below.
It is actually better to estimate a temperature about 10ºC (50ºF) lower when deciding the mixing rate.
Mixing rate of water and antifreeze
Min. °C
atmospheric
°F
temperature
liters
Amount of
antifreeze
US gal
liters
Amount of
water
US gal
Cleaning inside of cooling system
and changing coolant
Every year (autumn)or every 2000
hours whichever comes first
Every 6 months (spring, autumn)
(Drain antifreeze in spring, add anti-
freeze in autumn)
Every 6 months or every 1000 hours
whichever comes first
-10 -15 -20
14 5 -4
13.2 15.8 18.0
3.48 4.17 4.75
30.8 28.2 26.0
8.13 7.44 6.86
WARNING
-25 -30
-13 -22
20.2 22.0
5.33 5.81
23.8 22.0
6.28 5.81
SERVICE PROCEDURE
Replace corrosion resistor
Every 500 hours and when clean-
ing the inside of the cooling sys-
tem and when changine coolant
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