How to Pick a Used Excavator in Good Condition
Compared with new excavators, the second-hand ones with higher cost performance undoubtedly become another fairly good choice. Here are some useful tips when picking a used excavator.
1. Check bucket and boom
Excavators are not always used as a digging machine, builders sometimes use them to drive piles or lay pipelines. Therefore, you need to pay attention to the condition of the bucket to ensure that there are no problems with the piling, crushing and traveling devices. Another important part is that it is necessary to check the tightness of the bucket cylinder connecting pin and bushing. Many problems are caused by neglect of maintenance and inspection. Another key point is to carefully look at the part where the rear arm connects to the excavator. If the connection under the rear arm wears too much, it may lead to the loss of the value of the entire equipment.
2. Check hydraulic cylinders and oil lines
Oil leakage means that the entire oil circuit may be contaminated. It is very important to check the hydraulic cylinder and oil pipe. The best situation is that the chrome finish of the hydraulic cylinder has no scratches, dents or signs of oil leakage. If there is hydraulic oil seeping, dust may have contaminated the hydraulic system. Also make sure the cylinder walls are not damaged or dented. The gap between the oil cylinder and the cylinder wall is very small, as long as there is a sundry in the pipeline, it will cause the oil cylinder to produce a large amount of metal chips due to wear during operation, and remain in the hydraulic system.
3. Check rubber tracks and undercarriage
The rubber tracks on a mini excavator, unlike the steel tracks on larger machines, are designed for use on grass and driveways. Many times users do not check the wear of rubber tracks as closely as they check steel tracks. As a result, only the wear of the rubber track was seen, but not a lot of wear on the sprockets and idlers. The condition of the rubber tracks can be estimated by inspecting them for cracks and edge wear.
When you check the tracks and undercarriage, don't forget to check the oil level and cleanliness. If the oil level is already low and water or something gets in, that's going to cause more trouble.
4.Driving operation check
After the engine is warmed up and started, tilt the machine so that it can only stand on one side of the track, and alternate the tracks on both sides in turn to stand. Note how many times you can do this in 30 or 60 seconds, and compare it to other crawlers. The crawler of the excavator is a built-in flow meter, if the two do not have the same flow, then there is a problem.
Another detection method is to drive the excavator to run for 10 meters on flat ground. If it runs in a straight line, you can know that the running conditions of the traveling devices on both sides are equally good. Also check the slewing ring gear and slewing bearings. Normally, the upper section starts the swing smoothly and stops accurately with little or no deviation. For small excavators, the slewing ring gear and slewing bearing should have the same long life as the machine, so any questions about this part must be paid attention to.
5. Check the engine hood
You should open the hood and check the exhaust duct for signs of smoke, or pull out the dipstick and check for smoke. Excessive smoking usually indicates that the piston rings need to be replaced, and it may not be long before the engine is overhauled.
Check the air filter unit and all tubing and clamps. Just a little bit of dust is enough to destroy an entire engine. Be aware of dust or dirt that has accumulated on the terminals. Also check the fan to make sure the belts are taut. Check the radiator to make sure it is clean. Neglecting the cooling system and air intake system will likely cause the engine to overheat and shorten the life of the machine.
Basic checks also include checking the radiator fluid and engine oil, checking the battery for corrosion, and looking for any obvious leaks around the engine.