Komatsu GD555-5 Operation & Maintenance Manual page 218

OPERATION OPERATION
3. Set gear shift lever (4) to the P (PARKING) position while
pressing its knob. The parking brake lamp lights up at the same
time.
4. Operate the work equipment control lever, and lower the blade
and the ripper (or the scarifier) to the ground.
WHEN SELECTING TORQUE CONVERTER AUTO MODE
1. Release accelerator pedal (1).
OPERATION OPERATION
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