1. Failure phenomenon
The pilot control valve, main operation valve spool, anti-slip valve, overload charge valve, hydraulic cylinder oil seal, etc., caused the boom, stick and bucket hydraulic cylinder to slip.
2. Trouble diagnosis and troubleshooting steps
(1) Check whether the slippage of each hydraulic cylinder is within the specified range (slippage of boom, arm and bucket hydraulic cylinder is less than 20mm/5min), if it is within this range, it means that the hydraulic cylinder is normal
(2) If the slippage of the hydraulic cylinder exceeds the specified range, first close the pilot shut-off valve to check whether the slippage of the hydraulic cylinder has decreased. If the slip amount decreases, it means that the pilot control valve is faulty; if the slip amount does not decrease and continues to increase, check the boom spool valve and the five-way directional valve in the four-way directional valve in the main operation valve Whether the inner stick slide valve is adjusted correctly. If it is not adjusted, readjust and lock it.
(3) If the anti-slip valve is adjusted correctly, but the hydraulic cylinder still continues to slip, you should temporarily replace the overload charge valve in the other hydraulic cylinder's oil circuit to check whether it still slips.If it does not slip, then explain The overload charge valve is faulty; if it continues to move, check the hydraulic cylinder for internal leakage
(4) If the hydraulic cylinder leaks, replace the hydraulic cylinder seal; if the hydraulic cylinder does not leak, it indicates that the main operation spool is scratched, the spring is damaged or the end of the spool is loose.
