There is no water in it. General analysis believes that the cylinder sleeve seal may be damaged. Then, the three lower cover plates on the machine body were opened first, then the water tank was filled with water, and the port was additionally ventilated and pressurized. As a result, it was found that there was a large amount of water from the cylinder wall opposite the position of the lower cover plate of the first cylinder. There was no leakage, but there was no water seepage around the underside of the cylinder liner, and no water droplets were found at the lower end of the connecting rod. This phenomenon showed that the water jacket of the cylinder liner was not damaged. The engine oil was also removed and the cooling water leaked and flowed. ※ The inlet and outlet 48 of the heater at the fault location were blocked, and the water pump 4 and the body water chamber 8 were blocked. The leak test result showed that the leaking phenomenon disappeared. Inside the oil radiator. Then, using the same method to leak check the oil radiator, that is blocking 8 people, from the discharge switch 0 ventilation pressure, the results of the leakage phenomenon occurred again; remove the fine filter of the rotor housing, and again tested with this method The fine filter was filled with water; finally it was found that the water flowed from the oil filter to the sump. Through the above inspection tests, it is proved that the failure is caused by welding of the radiator of the oil radiator in several minutes before the engine stops working. That is, the oil pressure and the cooling water pressure are basically the same at the time and the oil and water do not permeate with each other, but the oil pump stops after the engine stalls. Work, oil pressure close to zero, and the tank has a fixed height, when the pressure of cooling water is greater than the oil pressure, cooling water is along the line of water pump pump oil radiator core core weld at the end of the oil coarse filter oil fine filter oil pan flow with dashed line The seepage flow path causes water to flow outward from the edge of the oil gauge hole. The oil radiator was dismantled and the position of the welding seam was found. The fault was removed after rewelding. The above special faults can easily cause people to misjudge. We did not blindly dismantle, but carefully observed the test and comprehensive analysis to determine the correct conclusions, to quickly and accurately eliminate the fault. According to Dongfenghong 75 bulldozer hydraulic system working principle analysis, the possible causes of hydraulic cylinder sinking are oil seal damage on the piston; cylinder wall is seriously strained; 0-ring seal between piston rod and piston is damaged; guide sleeve and cylinder tube The zero-shaped seal ring was damaged; the seal ring between the guide sleeve and the piston rod was damaged; the guide sleeve was cracked; and the piston rod was scratched. However, after inspection and testing, the above parts are normal. After careful analysis, it was thought that the fault might be on the valve. Remove the pilot valve and blow the pilot valve of the inlet valve with compressed air to the neutral position and check the two oil outlets leading to the hydraulic cylinder. Under normal circumstances, when the control valve is in the neutral position, the oil inlet and the two oil outlets should not communicate with each other, but at this time it is found that both outlets have air bubbles, indicating the cooperation of the valve stem and the valve body The gap is so large that the tight seal causes the upper and lower chambers of the hydraulic cylinder to communicate with each other. Even if the hydraulic oil in the hydraulic cylinder has a rod cavity, the hydraulic oil enters the control valve under the action of the weight of the blade and enters the valve through the gap between the valve stem and the valve body. The hydraulic cylinder is submerged in the hydraulic circuit of the hydraulic cylinder without a rod chamber or through the return oil passage into the hydraulic oil tank. After repair and processing, the normal fit clearance between the valve stem and the valve body is restored, and the fault can be eliminated. Stevia TSG,High Quality Stevia TSG,Stevia TSG Details, CN JINING USP INTERNATIONAL CO.,LTD. , https://www.uspintl.com