Details: JCB's machine has been working for more than 9000 hours. The excavator is working on the construction site and is not used for breaking Recently, when the control lever is operated to lift the boom or extend the jib, the boom and the jib move slightly in the opposite direction before moving
Analysis by JCB excavator repair shop: if JCB excavator moves slowly when the boom is lifted or the jib is extended, it may be caused by internal leakage of the oil cylinder.
Troubleshooting:
Repair the failure of slow action of lifting boom and jib of JCB excavator. Check whether the load check valve in the control valve works correctly: No, it means the load one-way valve is faulty. Yes, continue to check whether the anti drift valve of the jib or boom is stuck or stuck. Yes, it means the anti drift fault. No, it means the anti drift fault is inside the oil cylinder?
In the initial stage of operation, the oil pressure and flow from the oil pump are low. Therefore, if the load check valve fails, the oil at the bottom of the boom cylinder flows back to the oil path through the load check valve, so that the boom cylinder temporarily retracts. If the clearance between the piston and the cylinder is poor, the oil pressure at the bottom will leak to the rod side. Since the oil pressure and flow from the oil pump are low at the initial stage of operation, if the oil leakage through the gap between the piston and the casing is large, the oil cylinder will temporarily retract. In addition, the force of the oil cylinder also decreases. In this case, the drift of the cylinder also increases.
