Buy used excavators precautions, start checking Step 1: Start the engine warm-trading company used digging machine, tilt the machine to make it stand alone crawler side, followed by rotation were standing on both sides of the crawler. Note that within 30 seconds, or 60 seconds the number of times such an operation can be completed, and then to compare with other tracks. Excavator crawler device is a built-in flow meter, if the two do not have the same flow of second-hand excavator sale, then there is a problem. Excavators why orifice blockage affects so big? This is a common fault, but also a great influence on the hydraulic system failure. To clarify the truth Shijiazhuang sale of second-hand excavator, should be introduced on pilot safety valve works. P pressure oil through existing orifice into the cavity C, then C chamber pressure P is equal to the system pressure. Because of the role of small springs modern digging machine used sale, pistons have been pressed against the right side of the seat. When the oil pressure chamber C up to a certain value. That is up to the cone valve regulator value, the poppet valve open, the oil chamber C through the cone valve back to the tank. In this case, C chamber pressure plummeted, due to the damping effect of orifice, C chamber and system pressure loss of balance, so the small piston back to the left, the system pressure through a small piston overflow tank. When the system pressure falls below a certain value, the cone valve is reset, followed by a small piston has the right to reset. So repeatedly performed to adjust the system pressure. If the small piston in the middle of the damping holes are blocked, lack of oil pressure, C chamber pressure chamber C is much lower than the system pressure, so the smaller piston has been in the left position. System pressure regardless of level, are also in the overflow state. So when the tiny orifice once blocked, the impact will be great. Kim Ho used excavators sale, Lianyungang sale of second-hand excavator, digging machine used Guangdong sale by Shanghai Jin Hao Used Construction Machinery Co., Ltd .. Shanghai Jin Hao Used Construction Machinery Co., Ltd. (www.jinhaosh.cn) strong, credible, in Shanghai Minhang District of mining machinery industry has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead jinhao Excavators and you work into the brilliant, for a better future!