Views: 0 Author: Site Editor Publish Time: 2026-05-21 Origin: Site
Troubles in the systems for lifting operations
Table1
System | Trouble | Cause | Solution |
|---|---|---|---|
Outrigger system | Inoperative | Too low pressure setting of relief valve in the chassis multi-way valve | Adjust |
Dirt blocks up relief valve element | Disassemble and clean | ||
Control valve faulty | Repair | ||
Outriggers fail to extend out/retract in, or move sluggishly | Relief valve faulty | Check the relief valve for normal operation. | |
Low system pressure | The pressure of sequence valve cannot reach the required value | Adjust the pressure of sequence valve | |
Solenoid valve faulty | Check if the solenoid valve is energized. | ||
Oil cylinder piston sealing is damaged | Replace the sealing | ||
Pilot check valve of jack cylinder inoperative | Repair or replace the check valve | ||
Low pressure setting of relief valve | Adjust the pressure setting | ||
Jack retracts or extends automatically | Large leakage in oil pump | Replace the oil pump | |
Internal leakage in oil cylinder | Replace the sealing or cylinder. | ||
Sluggish movement | Faulty inner part of control valve | Repair | |
Excessively low pressure setting for relief valve | Adjust | ||
Jack automatically retracts or extends during operation or road travel | Double-way hydraulic valve faulty | Clean or replace the hydraulic double-way lock | |
Internal leakage in oil cylinder | Replace the sealing or cylinder | ||
External leakage in oil cylinder | Repair | ||
Pilot check valve of jack cylinder inoperative | Repair or replace the check valve. | ||
Slewing system | Brake inoperative | Brake lining is worn or there is oil on brake lining | Repair or replace |
Air entered brake oil circuit | Bleed air | ||
Brake cylinder is faulty | Repair | ||
Slewing operation cannot be performed | Internal leakage in slewing pump | Repair or replace | |
Internal leakage in slewing motor | Repair or replace | ||
Slewing reducer faulty | Repair | ||
Pilot lever faulty | Repair | ||
Inoperative slewing brake solenoid valve | Clean or replace | ||
Slewing brake is faulty | Check and repair | ||
Retarded slewing operation | Internal leakage in slewing motor | Repair or replace | |
Internal leakage in slewing pump | Repair or replace | ||
Insufficient pilot pressure | Check and repair | ||
Large shock at slewing starting | Pilot lever faulty | Check and repair | |
Unsteady slewing brake | Slewing brake is faulty | Check and repair | |
Damper valve faulty | Check and repair | ||
Free slewing | Free-swing of slewing system inoperative and free/lock change system inoperative | Solenoid valve stuck or the valve electric circuit faulty | Clean or replace |
Inoperative slewing brake solenoid valve | Clean or replace | ||
Insufficient inlet oil pressure of brake | Slewing buffer valve faulty | ||
No slewing movements | Insufficient pressure of slewing brake | Check the slewing brake solenoid valve | |
Insufficient pressure of main oil circuit | Check the free-swing solenoid valve | ||
Winch system | Hook cannot be lifted | Excessively low pressure setting of relief valve in multi-way valve | Regulate the pressure |
Hydraulic motor faulty | Check and repair | ||
Insufficient main pump pressure | Check and repair | ||
Hydraulic pilot lever faulty | Check and repair | ||
Unloading relay faulty, in unloading state. | Check and repair | ||
Faulty LMI: the unloading signal of LMI cannot be released | Check and repair | ||
Winch brake faulty | Check and repair | ||
Hook cannot be lowered | Winch counterbalance valve faulty | Check and repair | |
Control oil circuit of counterbalance valve blocked | Check and repair | ||
Winch brake faulty | Check and repair | ||
No pressure in brake oil inlet circuit | Check the counterbalance valve | ||
Hydraulic pilot lever faulty | Check and repair | ||
Faulty pilot valve | Check and repair | ||
Serious leakage in winch motor | Repair or replace | ||
Brake inoperative | Oil on brake friction disc | Clean | |
Friction disc worn | Adjust or replace | ||
Air in brake oil circuit | Bleed air | ||
Internal leakage in brake oil cylinder | Replace the sealing | ||
Boom and telescoping system | Boom cannot extend | Excessively low pressure setting of relief valve in the multi-way valve | Regulate the pressure |
Rope out of groove | Repair or replace | ||
Internal leakage in telescoping cylinder | Replace the sealing | ||
Insufficient main pump pressure | Check and repair | ||
Faulty LMI: the unloading signal of LMI cannot be released | Check and repair | ||
Pilot lever faulty | Check and repair | ||
Boom cannot retract | Excessively low pressure setting of relief valve for extending in telescoping control valve of superstructure multi-way valve | Adjust | |
Rope out of groove | Repair or replace | ||
Internal leakage in telescoping cylinder | Replace the sealing | ||
Insufficient main pump pressure | Check and repair | ||
Boom retracts during operation | The counterbalance valve is faulty and cannot be locked | Repair | |
Internal leakage in oil cylinder | Repair | ||
External leakage in oil cylinder, valve or piping joints | Repair | ||
Slow retracting boom speed | Telescoping control valve faulty | Check if the solenoid valve works normally | |
Cylinder can not retract | Telescoping counterbalance valve faulty | Check and repair | |
Counterbalance valve control oil circuit blocked | Check and repair | ||
Luffing system | No pressure or too low pressure in luffing system | Low hydraulic pump revolution speed or volumetric efficiency | Check the hydraulic pump, and repair or replace it |
Relief valve in superstructure combined valve damaged or pressure decreased | Repair or replace | ||
Luffing cylinder internal leakage or damage | Repair or replace | ||
Shaking occurs during luffing up or down | Too tight luffing cylinder | Repair or replace | |
The guide sleeve in luffing cylinder or nylon supporting ring on the piston is influenced by the environmental temperature and expands | Repair or replace | ||
Shaking occurs during luffing down | High opening pressure of luffing counterbalance valve | Adjust to specified value | |
Uncontrolled lowering when luffing | Inner damage of luffing cylinder | Repair or replace | |
Inner damage of luffing counterbalance valve | Repair or replace | ||
Cylinder cannot extend | Excessively low pressure setting of relief valve in the multi-way valve | Regulate the pressure | |
Severe internal leakage in luffing cylinder | Check and repair | ||
Insufficient main pump pressure | Check and repair | ||
Hydraulic pilot lever faulty | Check and repair | ||
Cylinder can not retract | Luffing counterbalance valve not open | Check and repair | |
Back pressure of main return oil circuit too high | Check and repair | ||
Counterbalance valve control oil circuit blocked | Check and repair | ||
Hydraulic pilot lever faulty | Check and repair | ||
Unloading solenoid valve faulty, in unloading state | Check and repair | ||
Faulty LMI: the unloading signal of LMI cannot be released | Check and repair | ||
Cylinder automatically retracts during operation | Internal leakage in oil cylinder | Repair or replace | |
The counterbalance valve is faulty and cannot be locked | Repair or replace | ||
Electrical system | No electricity in superstructure | Fuse F1 (50A) blown | Replace |
Starter switch is inoperative | Repair or replace | ||
Blown power source relay | Check the circuit and replace the relay | ||
Wire disconnected | Reconnect wire or lay cables | ||
Trouble in light circuit | Bulb damaged | Replace | |
Fuse blown | Replace | ||
Grounding faulty | Repair | ||
Switch inoperative | Repair or replace | ||
Wire disconnected | Reconnect wire or lay cables | ||
Anti-two-block inoperative | Cord reel faulty | Repair or replace | |
Wire disconnected | Reconnect wire or lay cables | ||
Anti-two-block switch inoperative | Replace | ||
Weight rope broken | Replace | ||
Solenoid valve inoperative | Repair or replace | ||
Solenoid valve grounding faulty | Repair | ||
Faulty grounding of anti-two-block switch | Repair | ||
LMI faulty | Contact XCMG service station | ||
Wipers inoperative | Fuse blown | Replace | |
Switch inoperative | Replace | ||
Motor damaged | Repair or replace | ||
Grounding faulty | Repair | ||
Wire disconnected | Reconnect wire or lay cables | ||
Solenoid valve inoperative | Wire disconnected | Repair | |
Poor contact or looseness of plug-ins | Repair | ||
Solenoid valve burned out | Replace | ||
Solenoid valve spool faulty | Repair | ||
Hydraulic system | Noise from hydraulic pump | Insufficient oil | Refill |
Air enters into the suction line | Repair and bleed air. | ||
Loose mounting bolts | Tighten | ||
Hydraulic oil contaminated | Replace the oil or filter it | ||
Drive shaft vibrated | Repair | ||
Universal joint worn | Replace | ||
Hydraulic pump faulty | Repair or replace | ||
No pressure in hydraulic motor | Severe leakage in motor | Check the leakage in motor | |
Normal leakage in hydraulic motor, but can not lift the load | Motor variable mechanism is faulty | Repair | |
Incorrect adjustment of adjusting bolt | Readjust the bolts |
Note: please supply VIN, serial No., engine serial No. and delivery date when professional maintenance is required. Refer to “ Product serial number ” in the Physical Information and Rated Load Charts Manual for details.
