Daewoo excavator slow working action:What are the common causes of a Daewoo excavator's slow working action?

Q: What are the common causes of a Daewoo excavator's slow working action?

A: According to the Daewoo Excavator Service Manual, slow working action is often caused by hydraulic system issues, including low hydraulic oil levels, clogged filters, worn hydraulic pumps, or faulty relief valves. The manual emphasizes checking the hydraulic oil quality and filter conditions first, as contaminated oil can reduce flow and pressure. Additionally, engine performance problems, such as a clogged air filter or fuel system issues, can lead to reduced power output and slower hydraulic response. The manual recommends a systematic diagnostic approach, starting with pressure tests at the main pump and control valve to identify the root cause. Regular maintenance per the manual helps prevent such issues.

Q: How does hydraulic oil condition affect Daewoo excavator working speed?

A: The Daewoo Excavator Operation and Maintenance Manual states that hydraulic oil condition directly impacts working speed. Degraded or contaminated oil reduces lubrication and increases internal leakage in pumps and valves, leading to slower cycle times. The manual specifies that oil should be checked daily for level and contamination, and replaced at recommended intervals (typically every 2000 hours). Using the correct oil grade (e.g., ISO VG 46) is critical. If oil is dark or contains particles, it can cause wear and sluggish operation. The manual also notes that maintaining proper oil temperature (40-60°C) is essential, as cold oil increases viscosity and slows action until warmed up.

Q: What role does the main hydraulic pump play in Daewoo excavator slow action?

A: Per the Daewoo Excavator Service Manual, the main hydraulic pump is the heart of the system. If the pump is worn or damaged, it cannot deliver sufficient flow and pressure, resulting in slow working action. Common signs include reduced digging force and sluggish boom, arm, and bucket movements. The manual details that pump performance should be tested with a flow meter; a flow rate below specification indicates internal wear. Additionally, the pump's regulator or compensator may be faulty, causing poor response to load demands. The manual advises overhauling or replacing the pump if worn beyond limits, and calibrating the pump control system after repair.

Q: How can I diagnose a Daewoo excavator with slow working action?

A: The Daewoo Excavator Troubleshooting Guide outlines a step-by-step diagnosis for slow working action. First, check hydraulic oil level and filter, then test main relief valve pressure. If pressure is low, adjust or replace the valve. Next, perform a flow test on the main pump; if flow is low, the pump may need repair. Also, check pilot pressure and control valve spools for sticking. The guide stresses using a pressure gauge set and following the sequence to isolate the issue. Additionally, inspect the engine for power loss, as engine speed affects pump output. Always refer to the guide for model-specific values.

Q: What maintenance practices prevent slow working action in Daewoo excavators?

A: According to the Daewoo Excavator Maintenance Manual, preventive maintenance is key to avoiding slow working action. It recommends daily checks of hydraulic oil level, filter indicator, and leaks. Every 500 hours, replace hydraulic filters and inspect hoses. Every 2000 hours, change hydraulic oil and clean the suction strainer. The manual also advises regularly testing hydraulic pressures and adjusting relief valves as needed. Keeping the cooling system clean ensures proper oil temperature. Additionally, following the engine maintenance schedule (air filter, fuel filter) prevents power loss. Adhering to these intervals maintains optimal performance and prevents sluggish operation, extending component life.

Dialogue about

Common scenarios of "Daewoo excavator slow working action"

【Customer】 Hi, I have a Daewoo excavator that is working very slowly. Can you help me diagnose the problem?

【Technician】 I'll try my best. Can you tell me which model it is and when the problem started?

【Customer】 It's a Daewoo Solar 220LC-V. The slow operation started gradually over the past week.

【Technician】 Gradual onset suggests a progressive issue. Does the engine seem to struggle or produce black smoke?

【Customer】 No black smoke, and the engine sounds normal. But all functions are slow, including boom, arm, and bucket.

【Technician】 If all functions are slow, it could be a hydraulic pump issue or a problem with the main relief valve. Have you checked the hydraulic oil level?

【Customer】 Yes, the oil level is fine. The oil looks clean too. What else could cause this?

【Technician】 Could be a clogged hydraulic filter or a failing pump. When was the last time you changed the hydraulic filter?

【Customer】 I changed it about 500 hours ago. The manual says every 1000 hours, so it should be okay.

【Technician】 That should be fine. Another possibility is a faulty negative control valve or a pilot pressure issue. Does the excavator have any error codes?

【Customer】 No error codes on the display. But I noticed the pilot pressure gauge reads lower than usual.

【Technician】 Low pilot pressure can cause slow operation. Check the pilot pump and the pilot relief valve. Also inspect for any leaks in the pilot circuit.

【Customer】 I'll check for leaks. If that's not it, what about the main hydraulic pump?

【Technician】 Yes, the main pump could be worn. You can test it with a flow meter. If flow is below spec, the pump needs rebuild or replacement.

【Customer】 How do I test the main pump flow?

【Technician】 You'll need a hydraulic flow tester. Connect it in line with the pump outlet. Measure flow at rated pressure and compare to specifications.

【Customer】 That sounds complicated. Is there a simpler check?

【Technician】 You can also check the pump's case drain flow. Excessive flow indicates internal wear. But a flow test is more accurate.

【Customer】 Okay, I'll try to find a flow tester. In the meantime, could the issue be electrical?

【Technician】 Yes, if the pump is electronically controlled, a faulty sensor or wiring could cause slow response. Check the pump controller for error codes.

【Customer】 Thanks, I'll check the controller and pilot pressure. I appreciate your help.

【Technician】 You're welcome. Let me know what you find, and we can narrow it down further.