Fault Phenomenon: SANY SKT105 wide body mining truck when operating the hoist, the dump body lifts significantly slower, and engine RPM drops noticeably.

Troubleshooting Process:
– Checked main pump: hoist pump severe internal leakage, insufficient flow.
– Checked relief valve: hoist system relief pressure set too low.
– Checked cylinder: hoist cylinder piston seals worn, internal leakage.
– Checked pilot pressure: insufficient pilot control pressure.

Root Cause: The internal valve plate of the hoist hydraulic pump is worn, reducing volumetric efficiency and failing to provide sufficient flow and pressure.

Required Parts: Repair or replace hoist hydraulic pump.