Fault Phenomenon: Terex AC1000 when setting up outriggers, one side slowly retracts without operation.

Troubleshooting Process:
– Checked outrigger lock valve: spool stuck.
– Checked outrigger cylinder internal leakage: pressure holding test failed.
– Replaced outrigger hydraulic lock (bi-directional lock valve).

Root Cause: The outrigger hydraulic lock spool was stuck due to contamination, failing to lock the oil circuit effectively.

Required Parts: Outrigger hydraulic lock assembly.