Fault Phenomenon: Effepi truck crane when unfolding the knuckle boom, the two cylinders move at different speeds, causing the boom to twist.

Troubleshooting Process:
– Checked flow divider valve: flow divider stuck.
– Checked cylinder back pressure: significant back pressure difference.
– Cleaned flow divider valve, adjusted lines.

Root Cause: The hydraulic flow divider valve was stuck, causing uneven flow distribution.

Required Parts: Flow divider valve repair kit.