Komatsu PC78US-6 Operation & Maintenance Manual page 179

OPERATION
HOW TO LOWER WORK EQUIPMENT WHEN ENGINE STOPS DUE TO ABNORMALITY
Before loosening the plug, thoroughly check safety under the work equipment and the blade.
Never allow anyone to go under the work equipment or the blade.
While the work equipment is descending, keep holding the plug with a tool, so that the descent may be stopped any moment.
NOTICE
Do not loosen the plug by more than 5 turns. Otherwise the plug goes off
and the hydraulic oil will spurt out.
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TROUBLES AND ACTIONS
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