What is the reason why it feels heavy (almost unable to move) when turning the excavator walking control handle? Pulling the excavator walking distribution valve is different from other distribution valves. The walking distribution valve of most machines is not hydraulically controlled, but is directly pulled manually by a mechanical pull rod. Because the machine is old or the distribution slide valve has worn out, the matching gap between the walking slide valve and the hole has become larger, and high-pressure oil will leak from the oil passage through the slide valve gap to the end with the spring, and the spring cover is tightly covered outside the spring. At the same time, high pressure is formed in the cover, causing the distribution valve to shift to the spring side, the control lever is very heavy (the other direction is lighter). When the excavator is started by operating the two crawler walking joysticks at the same time, the engine speed will drop instantaneously, or even stall. What is the reason? This failure of excavators is more common. This is mainly due to a problem with the variable mechanism of the plunger pump. When the machine of the excavator is idling, the plunger pump still has a large flow. The travel oil motor of the excavator has just been repaired. The crawler will go faster when the throttle is low, but it will not go when the throttle is high. What is the reason and the remedy? This is because the valve plate was ground during maintenance of the drive gear of the excavator. Too much grinding makes the pressing force between the valve plate and the cylinder block surface insufficient. Because the oil pressure is low when the throttle is small, it is not easy to leak between the plane and the plane; when the oil pressure is increased, the oil pressure between the planes is overflow, which causes the crawler to not move when the throttle is high. The remedy for this situation can be to add a washer to the spring, if it is a butterfly spring, you can add one more butterfly spring.