Komatsu PC78US-6 Operation & Maintenance Manual page 214

MAINTENANCE
MAINTENANCE PROCEDURE
CHECK AND ADJUST RUBBER SHOE TENSION
There is danger of the plug (4) flying out under the high internal pressure
of the grease. When loosening plug (4), never loosen it more than one turn.
Never loosen any part other than plug (4). Never put your face in line with
the mount of plug (4).
If the Rubber shoe tension is not relieved by this procedure, please contact
your Komatsu distributor.
Increasing Track Tension
NOTICE
The standard value is low, so be careful not to tighten the rubber shoe too much.
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