2. Observe whether there are knocking marks on each oil cylinder. If there is knocking sound, it proves that the machine has been seriously damaged, and the oil cylinder will always leak oil. Even if the oil seal is replaced, it will continue to leak oil in a short time. Therefore, it is very important to check the oil cylinder when buying second-hand machines.
3, check the four-wheel area, first observe whether the driving wheel, guide wheel, roller, roller and crawler are seriously worn. Secondly, check whether the chain is original. There is a sign on the chain. If this sign corresponds to the information of the machine, the chain is original. If it doesn't match, it means that the chain has been changed, and the machine may be seriously worn, so you should buy it carefully.
The engine is commonly known as the "heart" of the excavator, so be sure to check the engine carefully when buying the second-hand machine. When testing, listen to whether the engine is noisy, whether the power is strong, and whether the speed drops when working. At the same time, you can also enter the system to observe whether the exhaust volume is large. If the exhaust volume is large, it proves that the engine works for a long time and needs to be overhauled.
5. When you buy a second mobile phone, you should check the rotating motor to see if it rotates strongly and makes a lot of noise when it rotates. If there is noise, it is necessary to observe which part makes the noise, and then carefully observe whether there is a gap in the rotating chassis. Secondly, you should also carefully observe the distributor of the excavator. Because the function of the distributor is mainly to control the movements of various tasks, you must see whether the various working movements of the excavator are coherent and whether there is a pause when buying a second mobile phone for trial operation.
6. The hydraulic pump is the power component of the hydraulic system. Its function is to convert the mechanical energy of the prime mover into the pressure energy of liquid, and the oil pump in the hydraulic system provides power for the whole hydraulic system. Therefore, the inspection of hydraulic pump is also very important. When buying a second mobile phone, you should touch the hydraulic pump with your hands to see if there is any feeling of shaking your hands, then check whether the hydraulic pump has cracks and serious oil leakage, and try it out to see if the hydraulic pump has power and noise.
7, check the electrical system, whether all circuits can work normally, and then enter the computer system to check the motherboard, whether you can see the working conditions after entering the system, such as revolutions, pressure, maintenance mode, etc. , which proves that the computer board is normal.
Extended data:
Second-hand excavators are one of the main means of production in economic construction and the inevitable product of economic development. As a model of saving resources, second-hand excavators support national construction and development! The second-hand excavator industry in China developed rapidly in the middle and late 1990s. It not only saves a lot of natural and human resources for the country, but also plays an indelible role in the national economic construction.
In foreign countries, there is also an increasingly mature mechanical equipment recycling technology called "reman" in English. Refers to the second-hand or waste machinery and parts (produced parts meet the standards of new products) remanufactured, reprocessed and assembled machine products, known as remanufactured construction machinery. This technology is also emerging in China.
References:
Second-hand excavator-Baidu encyclopedia