Fault Phenomenon: General manual pallet truck lifting weak, oil turns black.

Troubleshooting Process:
– Checked oil color: oil black.
– Checked for impurities: excessive contaminants.
– Checked for water: water present.
– Checked replacement interval: oil not changed.

Root Cause: The hydraulic oil was not changed for a long time and has deteriorated.

Required Parts: Hydraulic oil change.