I buckets and cantilever excavators are not always used for digging, but sometimes they are also used for piling or laying pipelines. Therefore, users need to pay attention to the situation of the bucket to ensure that there is no problem with the piling, crushing and walking devices. Another important part is the connecting pin and bushing of the bucket cylinder, so check the tightness of these parts. When the user starts the machine to move the bucket, forearm and rear arm, he may see the movement of the pin shaft or cylinder, but the forearm and bucket do not move, which is caused by the looseness of the pin shaft and bushing. Another key point is to carefully check the connection between the boom and the excavator. If the connection under the boom is excessively worn, it may lead to the loss of the whole equipment value.
Second, oil leakage means that the whole oil circuit may be polluted. It is very important to check the hydraulic cylinders and pipes. In the best case, the chrome-plated surface of the hydraulic cylinder has no scratches, dents or oil leakage. If hydraulic oil leaks, dust may pollute the hydraulic system. Also make sure that the cylinder wall is not damaged or dented. The gap between the cylinder and the cylinder wall is very small. As long as there are sundries in the pipeline, a large number of metal chips will be produced due to the wear of the oil cylinder during work and remain in the hydraulic system.
Third, be wary of welding on the car body. Look carefully at the excavator for cracks and welding traces left by the original factory. These things show that this machine has been overused. Another good method is to put a straight board between the back arm and the stick to see if there is any dislocation or distortion. Pay special attention to the repair of redundant steel plates. If there are too many patches on the machine, it may mean that the equipment has been used for a long time.
Fourth, pay attention to rubber tracks and chassis. Many times, users will not check the wear of rubber tracks at close range like steel tracks. It is easy to ignore the large amount of wear and tear of sprocket and idler. Users can estimate the usage of rubber tracks by checking cracks and edge wear, just like paying attention to tire lines when watching tire wear. Don't forget to check the oil level and cleanliness when the user checks the track and chassis. This part is easily overlooked. If the amount of oil is already small, water or other things will enter, which will cause more trouble.
Verb (the abbreviation of verb) checks the operation of the excavator after it is started. After the engine is warmed up, tilt the machine so that it can only stand on one side of the track, and rotate the tracks on both sides in turn to stand. Pay attention to how many times this action can be completed in 30 seconds or 60 seconds, and then compare it with other tracks. The crawler of excavator is a built-in flowmeter. If they don't have the same flow, there is a problem. Another detection method is to drive the excavator on the flat ground 10m. If it runs in a straight line, we can know that the running conditions of the walking devices on both sides are equally good. Also check the slewing gear ring and slewing bearing. Under normal circumstances, the upper part can start rotating smoothly and stop accurately with little or no deviation. For a small excavator, the life of the slewing gear ring and slewing bearing should be the same as that of the machine, so any questions about this part should be paid attention to.
6. Open the hood, check the hood and check the exhaust pipe for signs of smoking. You can pull out the dipstick and check whether there is smoke. Too much smoke usually means that the piston ring needs to be replaced, and it may not be long before the engine is overhauled. Check the air filtration device and all pipes and fixtures. Just a little dust is enough to destroy the whole engine. Pay attention to the dust or dirt accumulated in the terminal, and also check the fan to ensure that the tape is in a tight state, and check the radiator to ensure cleanliness. Ignoring the cooling system and air intake system may lead to overheating of the engine, thus shortening the life of the machine. The basic inspection also includes checking radiator fluid and engine oil, checking the corrosion degree of the battery and checking whether there is obvious leakage around the engine.
When buying a second-hand excavator, both novice and veteran can refer to the above information to make a correct evaluation and buy a second-hand excavator with low price and good car condition.