What are the reasons for the slow merging action of Komatsu 200-7?
2 Answers
The reasons for the slow merging action of Komatsu 200-7 are as follows: Low control pressure output from the pressure reducing valve: Under normal circumstances, the pressure reducing valve can reduce the output oil pressure of the main pump and stabilize it at 3.3 MPa, forming the control oil pressure. If the conical valve core on the pressure reducing valve does not close tightly due to excessively dirty oil, the output pressure of the pressure reducing valve will be lower than 3.3 MPa. At this time, no matter how the control handle is operated, the control oil pressure remains low, and the movement of the main control valve cores of various working devices is insufficient, resulting in a reduced flow to the working devices and causing the entire machine to lack power. Low overflow pressure of the main relief valve: The main relief valve limits the maximum pressure of the entire hydraulic system to 32.5 MPa. For pressures exceeding this value, the main relief valve will open to relieve pressure and protect the system from damage. If the small hole on the main relief valve core is blocked due to poor oil quality, causing the valve core to remain open, or if the set overflow pressure of the main relief valve is too low, the actual overflow pressure will be low, meaning the system pressure will be low.
When I operate excavators at work, the most frustrating issue is the slow merging movements. I've used the Komatsu 200-7 model a few times, and the problem usually lies in the hydraulic system. It could be due to insufficient or contaminated hydraulic oil—dirty oil flows slower, causing sluggish cylinder movements. Sometimes, a severely clogged filter can also hinder oil flow and affect operation. I often recommend checking the oil level and filter condition first. If that doesn’t solve it, then the pump or valves might be worn out. If this issue isn’t fixed early, work efficiency drops, and it’s incredibly stressful when deadlines are tight. Regular maintenance, like timely oil changes and filter cleaning, can prevent a lot of trouble.
