Modern excavators utilize integrated mechanical-electrical-hydraulic control systems. When diagnosing issues, technicians often focus on balancing interactions between the engine,
hydraulic pump, control valves, and external loads. Common symptoms of mismatched performance include engine speed drop, sluggish operation, and reduced digging power.
1. Engine Speed Drop
First, verify the engine’s actual power output. If it falls significantly below the rated capacity, perform these checks:
Inspect the fuel filter for clogs.
Check the fuel line for leaks or air ingress.
Assess wear on fuel pump components (plunger, injectors, delivery valves).
Ensure the air filter is clean and the turbocharger (if equipped) functions properly.
Monitor engine temperature and oil viscosity—overheating or thin oil can reduce cylinder compression.
Look for cylinder liner wear or valve leakage causing combustion gas leakage.
If the engine operates normally, the issue likely lies in the hydraulic pump’s flow rate or its compatibility with the engine’s power output.
2. Sluggish Operation
For older Hengwang excavators, gradual slowdowns are often due to natural wear. Worn components increase internal leaks, generating excess heat and reducing hydraulic/engine oil viscosity.
This leads to slower performance when warmed up, necessitating a full overhaul.
For sudden slowdowns in newer models:
Check electrical fuses for damage.
Verify pilot pressure levels.
Inspect the servo control valve and piston for sticking.
Diagnose distributor valve or hydraulic pump malfunctions.
3. Weak Digging Force
Scenario 1: Engine speed drops sharply under heavy loads.
Confirm engine power output.
Adjust the hydraulic pump’s swashplate angle to reduce displacement while maintaining speed.
Scenario 2: Engine maintains speed, but digging force remains inadequate.
Calibrate system pressure according to Hengwang’s specifications.
If pressure adjustments fail, inspect the relief valve, pump regulator, cylinder block, or piston assembly.
General Tips
Experienced operators often recognize patterns:
Machine veering during travel: Worn center swivel seals, uneven pump flow, or faulty travel motors.
Hydraulic cylinder drift: Failed relief valves or damaged cylinder seals.
Hengwang’s integrated design ensures optimal performance across mechanical, electrical, and hydraulic systems. Prioritize electrical checks first, followed by hydraulic circuits
(auxiliary → control → main) and mechanical components. Regular maintenance minimizes wear and extends equipment life.