Komatsu PC78US-6 Operation & Maintenance Manual page 227

MAINTENANCE
REPLACE BREAKER CIRCUIT ADDITIONAL OIL FILTER ELEMENT
After the engine is stopped, the parts and oil are at high temperature, so there is danger of burns. Wait for the temperature to
go down before starting the operation.
When removing the cap from oil filler port (F), turn it slowly to release the internal pressure, then remove it carefully.
NOTICE
For details of the replacement interval for the element, "MAINTENANCE INTERVAL FOR HYDRAULIC BREAKER (PAGE 4-15)".
MAINTENANCE PROCEDURE
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