Komatsu WA20-2, Operation & Maintenance Manual

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24. SERVICE PROCEDURE 24. SERVICE PROCEDURE
1. Stop the engine and remove radiator cap 1 slowly.
2. Prepare a container to catch the coolant, then open drain valve
2 at the radiator left lower portion and drain plug 3 at the side
of the cylinder block to drain the coolant.
3. After draining the water, close drain valve 2 and plug 3 , and
fill with city water.
4. When the radiator is full of water, start the engine and run it at
low idling.
Open drain valve
2 and plug 3 , run the engine at low idling, and
flush water through the system for 10 minutes.
When doing this, adjust the speed of filling and draining the
water so that the radiator is always full.
While flushing water through the system, watch carefully that
the water inlet hose does not come out of the radiator water
filler.
5. After flushing, stop the engine, open drain valve 2 and plug 3 ,
then close it again after all the water has drained out.
6. After draining the water, clean with a flushing agent.
For details of the cleaning method, see the instructions given
with the cleaning agent.
7. After cleaning, open drain valve 2 and plug 3 to drain all the
cooling water, then close them and fill slowly with clean water.
8. When the water comes up to near the water filler port, open
drain valve
2 and plug 3 , run the engine at low idling, and
continue to run water through the system until clean colorless
water comes out.
When doing this, adjust the speed of filling and draining the
water so that the radiator is always full.
9. When the water is completely clean, stop the engine, close drain
valve
2 and plug 3 .
10. Add cooling water until it overflows from the water filler.
11. To remove the air in the cooling water, run for 5 minutes at low
idling, then for another five minutes at high idling.
When doing this, leave radiator cap off.
12. Drain the coolant inside sub-tank 4 , then clean the inside of the
sub-tank and fill again with water to a point between the FULL
and LOW lines.
13. Stop the engine, wait for about 3 minutes, add cooling water up
to near the radiator water filler port, then tighten the cap.