Fault Phenomenon: Komatsu GD655 grader blade cannot enter float mode, unable to adapt to ground contours.

Troubleshooting Process:
– Checked control valve: spool not reaching float position.
– Checked linkage: control handle linkage improperly adjusted.
– Checked cylinder: excessive cylinder back pressure.
– Checked solenoid valve: electric float valve faulty.

Root Cause: Improper adjustment of the blade control valve’s mechanical linkage prevents the spool from reaching the float position, failing to open the float oil path.

Required Parts: Adjust control valve linkage.