For some users who do not have much money, buying second-hand small digger no doubt less pressure, lower threshold, easy to achieve entrepreneurial dreams, so it is also a good choice. However, it should be noted that in recent two years, China’s large number of imported second-hand excavators, coupled with domestic circulation of second-hand excavators, that’s a huge quantity, and many of the appearance of second-hand equipment is difficult to simply identify after repaired. Therefore when the user wants to purchase a second-hand small digger, must measure from many aspects, avoids being duped.
1. Bucket and boom
Excavators are not always used for digging, but are sometimes used for piling or pipe laying, so users need to be aware of the condition of the bucket to ensure that the piling, crushing and walking devices are not faulty, there is an important part of the Bucket Cylinder Connection Pin, bushings, be sure to check the tightness of these places. When the user moves the bucket, Bar, and back arm, he may see the movement of the pin or cylinder, but the bar and bucket do not move because the pin and bushing parts become loose. Another key point is to take a close look at the part of the arm that connects to the excavator. If the joint below the arm is worn down too much, it may result in the loss of the value of the whole unit.
2. An oil spill means that the entire oil pipeline could be contaminated
It is very important to check the hydraulic cylinder and tubing. In the best case, there are no scratches, dents or oil leaks on the chrome-plated surface of the hydraulic cylinder. If there is hydraulic oil oozing out, the dust may have contaminated the hydraulic system. Also make sure the cylinder wall is not damaged or dented. The gap between the cylinder and the cylinder wall is very small, as long as there is debris in the pipeline, it will lead to the cylinder in operation due to wear and generate a large number of metal debris, and remain in the hydraulic system.
3. Watch out for excavator welds
Examine the excavator for cracks and welds that are not from the original construction, which indicate excessive use of the machine. Another good idea is to use a straight board in the back arm and bucket bar position to see if there is any misalignment or distortion. Special attention should be paid 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.
4. Watch the Pontoon and chassis
It’s easy to overlook the amount of wear and tear on the chains and panels. Users can check for cracks and edge wear in the Pontoon to assess its use, just as they can check for tread patterns when looking at tire wear. When checking the chassis, don’t forget to check the oil level and cleanness. This part is easy to miss. If the oil is low and water or something comes in, it will cause more trouble.
5. Check the operation after startup
After the engine is preheated and started, the tilting machine makes it stand on only one side of the track, and rotates the two sides of the track to stand in turn. Notice how many times you can do this in 30 seconds or 60 seconds, and then compare it to the other tracks. The crawler unit of the excavator is a built-in flow meter. If the two do not have the same flow rate, then there is a problem. Another way to test is to drive the excavator on flat ground for 10m. If the excavator is running in a straight line, it can be known that the two-way walking device is running as well. Also check the slewing gear ring and slewing bearing. Under normal circumstances, the upper part of the upper excavator can smoothly start and turn and can accurately stop, with little or no deviation. For Compact excavator, the slewing ring gear and slewing bearing should have the same length of life as the machine, so any questions about this part should be noted.
6. Open the engine hood and check
Open the engine hood and check the exhaust pipe for signs of smoke. pull out the dipstick and check for smoke. Too much smoke usually means that the rings need to be replaced, and it may not be long before the engine is overhauled. Check the air filter and all pipes and pipe clamps. Just a little dust will be enough to destroy the whole engine. Also check the fan to make sure the tape is in a tight state. Check the radiator to make sure it is clean. Ignoring the cooling system and intake system may cause the engine to overheat, to shorten the life of the machine. Basic checks also include checking the radiator fluid and engine oil, checking the battery for corrosion, and checking for any noticeable leaks around the engine.