Komatsu PC300LC-8 Operation & Maintenance Manual page 362

ATTACHMENTS AND OPTIONS
Replace Additional Breaker Filter Element
The parts and oil are at high temperature after the engine is stopped,
and may cause serious burns. Wait for the temperature to go down
before cleaning the engine breather.
When using compressed air, there is a hazard that dirt may be blown up
and cause serious injury.
Always use safety glasses, dust mask, or other protective equipment.
NOTICE
For details of the replacement interval for the element, see "MAINTENANCE INTERVAL FOR HYDRAULIC BREAKER (PAGE 4-17)".
Prepare a container to catch the oil.
1. Lower the work equipment to the ground and stop the engine.
2. Turn the starting switch to the ON position (B), then set the lock
lever to the FREE position (F).
3. After carrying out Step 2, operate each work equipment control
lever and attachment control pedal fully to the front, rear, left,
and right 2 or 3 times within 15 seconds to release the internal
pressure in the hydraulic circuit.
WARNING
MACHINE READY FOR ATTACHMENT
6 - 11