Loader bucket, boom, and steering movements depend on the hydraulic system. The control joystick and pilot valve are the “entry point” through which the operator’s commands enter the hydraulic system. Slow movement, no movement, or self-drift is often related to insufficient pilot control pressure or stuck valve spools.

The pilot valve outputs low-pressure pilot oil through the joystick to control the movement of the main valve spool, thereby changing hydraulic oil flow direction and flow rate. On the LIANYU Global product page, the 803004120 and 803688565 Control Joystick and Loader Joystick Control Pilot Valve are suitable for XCMG machinery. If the internal valve spool of the pilot valve is worn, the oil is contaminated, or the seal fails, problems such as slow movement, uncoordinated compound movements, and a heavy joystick may occur.

Common troubleshooting steps: First, check hydraulic oil cleanliness and oil level, because contaminated oil accelerates valve spool wear. Second, check whether pilot pressure meets the manufacturer’s standard. Third, check whether the joystick linkage and ball joints are loose. Fourth, check whether the pilot valve return oil is smooth. Maintenance recommendations include replacing hydraulic filters on time, avoiding mixing hydraulic oils of different brands, keeping pipes clean during repair, and bleeding air and testing each movement pressure after replacing the pilot valve. For loaders working at high frequency, the pilot valve is a vulnerable control component, and internal leakage should be dealt with promptly.