Komatsu GD555-5 Operation & Maintenance Manual page 279

SERVICE PROCEDURE SERVICE PROCEDURE
4. After the cooling fan reverse rotation pilot lamp on the machine
monitor flashes, check that it lights up. The fan is set to rotate
in reverse.
5. Run the engine at high idle.
Select the time for running the engine at high idle as follows according to the condition of clogging.
Normal clogging: 1 to 2 minutes
Excessive clogging: 2 to 3 minutes
6. When the cleaning is completed, run the engine at low idle.
7. Press position (B) of cooling fan reverse rotation switch (1).
8. After the cooling fan reverse rotation pilot lamp on the machine
monitor flashes, check that it goes out. The fan is set to rotate
in the normal direction.
9. Run the engine at low idle for approximately 10 seconds.
NOTICE
In case of cleaning only by using the reverse rotation of the cooling fan, mud and dirt possibly remain.
If switching the cooling fan rotation to the normal direction in this state, the mud and dirt probably stick fast again to the fin, etc.
After reverse rotations of the cooling fan, stop the engine and clear the remaining mud and dirt off by using compressed air or a
broom, etc.
In addition, confirm that there is no flammable material around hot portions of the engine.
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MAINTENANCE MAINTENANCE