Do you know what are the most common minor faults of excavators?
Posted: Jan 6th, '25, 21:29
Don't know that the gear oil is needed in the travel gearbox and turntable, and don't know how often it needs to be changed?
Can't figure out which is the oil filter and which is the diesel filter?
Don't know how to exhaust the air?
Don't know how many hydraulic oil filters there are?
If you encounter a small fault, it will be even more confusing.
Just like people have fever and colds, machinery often has some small problems. Some people say that excavator apprentices should start learning from bad machines, because small problems will appear more frequently. When you are proficient in driving skills, you will also understand a lot about mechanical maintenance. From this point of view, I am lucky. I have been dealing with bad machines for many years, so I have encountered many excavator faults. Here are some common ones. You can use them as a reference when you encounter the same case in the future, so you won't be helpless.
Many excavator drivers often encounter a problem, that is, the excavator cannot start. If it is a long-term inability to start, especially in winter, then congratulations, you may have a small vacation, because this is caused by the problem of the engine itself, it may be valve leakage or piston ring gap is too large, resulting in insufficient compression temperature, or other reasons, in short, it is not something that the excavator driver can solve. And in this case, it is not recommended to use engine starting spray. Although this thing works well, it will make the engine addicted like drugs.
If it is a temporary inability to start, for example, it was fine yesterday, but it can't start today, or it can't start just after stopping, in this case we can check the cause of the problem. In fact, the idea is also very simple. This temporary engine cannot start is nothing more than two reasons. First, the power is not connected, and second, the oil is not available.
The reasons should be considered in the following aspects:
1. Start the motor, no sound, indicating that there is no power. It is recommended to check whether the battery pile head is in poor contact or burned. If you are driving a Komatsu PC56 or Kobelco SK75, it is recommended that you first confirm that the hydraulic main switch is locked, because there are many models that cannot be started when the hydraulic main switch is not turned on. This is a very user-friendly design, but it will make some people who are just starting to get used to it for a while.
2. The starter motor is moving, but the speed is slow and the sound is weak, indicating that the battery power is insufficient. It is recommended to check whether the generator belt is normal. It is best to measure the power generation. If everything is normal, usually, you can only call the excavator owner and tell him two news, one bad news and one good news. The bad news is that the boss needs to pay for a new battery. The good news is that usually replacing the old battery with a new one can save some money.
3. The starter motor has a normal speed and sound, but the engine cannot start, indicating that the oil has not arrived. It is recommended that you clean the diesel pipeline to see if it is blocked. The two points that are easily blocked are the small filter at the bottom of the diesel tank and the hand oil pump. It is also possible that air entered when changing the filter element. Loosen the exhaust screw and pump oil with a hand oil pump to remove the air. It is worth mentioning that many small excavators use a certain engine of Yanmar, which cancels the hand oil pump and adds a small electronic oil pump to the oil pipe entering the diesel filter element. Therefore, we can hear the sound of the engine after turning on the power. This small electronic pump and the high-pressure electronic oil pump of the EFI are two completely different concepts. This small electronic pump only increases the flow of diesel in the oil pipe, but once there is a problem with this pump, it will also cause the engine to fail to start, or it will stall immediately after starting.
Excavator drivers sometimes encounter the opposite problem, that is, they cannot shut down the engine, the key is pulled out, and the engine does not shut down. This situation is usually caused by the flameout cable not being pulled. Open the engine cover by yourself and push the cable head into place to shut down the engine. The problem of the flameout cable will also cause it to fail to start.
4. Cold cars are easy to start, and hot cars are difficult to start. Different from the usual understanding, the symptoms of this situation are that it is easy to start in the morning or when the temperature is low. After the water temperature of the machine rises to a certain temperature, it cannot be started after shutting down and restarting. It must wait until the machine cools down before it can be started again. This situation is common in old machines. It is usually believed that the poor quality of diesel oil causes the wear of the diesel pump, which requires the oil pump to be calibrated. Calibration of the oil pump is a professional technical job, and the professionals and stores of oil pump calibration are mostly "Henan Oil Pump Calibration". It is said that there was an oil pump factory in Henan before, and then the oil pump factory went bankrupt. The masters in the factory opened oil pump calibration stores, and then relatives and neighbors followed suit. So now "Henan Oil Pump Calibration" stores are everywhere. I think they are probably the only group of people in China who do not want the domestic diesel oil quality to improve!
If you have gone through a lot of hardships and started the engine, and found that the excavator did not move at all, it can only mean that you are a sufficiently unlucky excavator driver. This symptom is like the lack of oil in the torque converter of the bulldozer. No matter how much you increase the throttle, the excavator does not move. If the hydraulic problem is excluded, there are two other reasons for this phenomenon in principle. The first is that the rubber block connecting the engine and the hydraulic pump is broken, causing the rotation of the engine main shaft to be unable to be transmitted to the hydraulic pump, but I think the probability of such a terrible thing happening is extremely low. The symptom of no movement may be caused by another reason, that is, your hydraulic main switch has failed. There are usually two designs for the hydraulic main switch of the excavator, one is direct control by hydraulic components, and the other is electronic component control. Nowadays, electronic components are mostly controlled, but they are also more likely to fail.
There are also some not very common situations, such as when you are driving an excavator in the mud, suddenly there is a booming noise from the hydraulic pump. In this case, it is recommended that you turn off the engine immediately. Because you may have encountered the most unfortunate situation in the history of excavator driving, that is, the walking oil pipe burst in the mud, and all the hydraulic oil leaked into the walking bracket. This is a very troublesome thing. Fortunately, I drive my own excavator and don’t have to listen to the boss’s roaring complaints. But the price I paid was: a set of clothes including shoes, a day’s time, and ten barrels of 18 liters of hydraulic oil.
There is another very scary and dangerous situation that few people have encountered, unless you are as unlucky as me, that is, the excavator cannot stop moving. As we all know, the operating handle of the excavator is an action in each direction. When the handle is in the middle position, the excavator will not move. But if the handle is in the middle position, the excavator will continue to move. Can you imagine how scary this is? Why does this phenomenon occur?
The reason why I encountered this situation is that a large amount of iron powder appeared in the hydraulic oil of the entire hydraulic system, causing the pilot switch (commonly known as the bullet head) to be stuck, or the small filter at the pilot switch to be blocked. And a large amount of iron powder in the hydraulic oil is from the travel reduction box to the hydraulic system.
There are also various symptoms of "mechanical cold", such as high engine water temperature, weak machine, and bubbles in the auxiliary water tank, that is, the cylinder mattress is flushed, which is a small problem, but if it is not handled, it will immediately cause big trouble. So we also need to observe more when we work, and prescribe the right medicine for various symptoms.
Choose BONOVO for high-quality, customizable brush cutters for skid steers with fast delivery. Contact us today to discover how our superior products can enhance your land management tasks!
for more info just visit our website at www.bonovogroup.com
contact # : +86 158 6218 2088
email : sales@bonovogroup.com
Can't figure out which is the oil filter and which is the diesel filter?
Don't know how to exhaust the air?
Don't know how many hydraulic oil filters there are?
If you encounter a small fault, it will be even more confusing.
Just like people have fever and colds, machinery often has some small problems. Some people say that excavator apprentices should start learning from bad machines, because small problems will appear more frequently. When you are proficient in driving skills, you will also understand a lot about mechanical maintenance. From this point of view, I am lucky. I have been dealing with bad machines for many years, so I have encountered many excavator faults. Here are some common ones. You can use them as a reference when you encounter the same case in the future, so you won't be helpless.
Many excavator drivers often encounter a problem, that is, the excavator cannot start. If it is a long-term inability to start, especially in winter, then congratulations, you may have a small vacation, because this is caused by the problem of the engine itself, it may be valve leakage or piston ring gap is too large, resulting in insufficient compression temperature, or other reasons, in short, it is not something that the excavator driver can solve. And in this case, it is not recommended to use engine starting spray. Although this thing works well, it will make the engine addicted like drugs.
If it is a temporary inability to start, for example, it was fine yesterday, but it can't start today, or it can't start just after stopping, in this case we can check the cause of the problem. In fact, the idea is also very simple. This temporary engine cannot start is nothing more than two reasons. First, the power is not connected, and second, the oil is not available.
The reasons should be considered in the following aspects:
1. Start the motor, no sound, indicating that there is no power. It is recommended to check whether the battery pile head is in poor contact or burned. If you are driving a Komatsu PC56 or Kobelco SK75, it is recommended that you first confirm that the hydraulic main switch is locked, because there are many models that cannot be started when the hydraulic main switch is not turned on. This is a very user-friendly design, but it will make some people who are just starting to get used to it for a while.
2. The starter motor is moving, but the speed is slow and the sound is weak, indicating that the battery power is insufficient. It is recommended to check whether the generator belt is normal. It is best to measure the power generation. If everything is normal, usually, you can only call the excavator owner and tell him two news, one bad news and one good news. The bad news is that the boss needs to pay for a new battery. The good news is that usually replacing the old battery with a new one can save some money.
3. The starter motor has a normal speed and sound, but the engine cannot start, indicating that the oil has not arrived. It is recommended that you clean the diesel pipeline to see if it is blocked. The two points that are easily blocked are the small filter at the bottom of the diesel tank and the hand oil pump. It is also possible that air entered when changing the filter element. Loosen the exhaust screw and pump oil with a hand oil pump to remove the air. It is worth mentioning that many small excavators use a certain engine of Yanmar, which cancels the hand oil pump and adds a small electronic oil pump to the oil pipe entering the diesel filter element. Therefore, we can hear the sound of the engine after turning on the power. This small electronic pump and the high-pressure electronic oil pump of the EFI are two completely different concepts. This small electronic pump only increases the flow of diesel in the oil pipe, but once there is a problem with this pump, it will also cause the engine to fail to start, or it will stall immediately after starting.
Excavator drivers sometimes encounter the opposite problem, that is, they cannot shut down the engine, the key is pulled out, and the engine does not shut down. This situation is usually caused by the flameout cable not being pulled. Open the engine cover by yourself and push the cable head into place to shut down the engine. The problem of the flameout cable will also cause it to fail to start.
4. Cold cars are easy to start, and hot cars are difficult to start. Different from the usual understanding, the symptoms of this situation are that it is easy to start in the morning or when the temperature is low. After the water temperature of the machine rises to a certain temperature, it cannot be started after shutting down and restarting. It must wait until the machine cools down before it can be started again. This situation is common in old machines. It is usually believed that the poor quality of diesel oil causes the wear of the diesel pump, which requires the oil pump to be calibrated. Calibration of the oil pump is a professional technical job, and the professionals and stores of oil pump calibration are mostly "Henan Oil Pump Calibration". It is said that there was an oil pump factory in Henan before, and then the oil pump factory went bankrupt. The masters in the factory opened oil pump calibration stores, and then relatives and neighbors followed suit. So now "Henan Oil Pump Calibration" stores are everywhere. I think they are probably the only group of people in China who do not want the domestic diesel oil quality to improve!
If you have gone through a lot of hardships and started the engine, and found that the excavator did not move at all, it can only mean that you are a sufficiently unlucky excavator driver. This symptom is like the lack of oil in the torque converter of the bulldozer. No matter how much you increase the throttle, the excavator does not move. If the hydraulic problem is excluded, there are two other reasons for this phenomenon in principle. The first is that the rubber block connecting the engine and the hydraulic pump is broken, causing the rotation of the engine main shaft to be unable to be transmitted to the hydraulic pump, but I think the probability of such a terrible thing happening is extremely low. The symptom of no movement may be caused by another reason, that is, your hydraulic main switch has failed. There are usually two designs for the hydraulic main switch of the excavator, one is direct control by hydraulic components, and the other is electronic component control. Nowadays, electronic components are mostly controlled, but they are also more likely to fail.
There are also some not very common situations, such as when you are driving an excavator in the mud, suddenly there is a booming noise from the hydraulic pump. In this case, it is recommended that you turn off the engine immediately. Because you may have encountered the most unfortunate situation in the history of excavator driving, that is, the walking oil pipe burst in the mud, and all the hydraulic oil leaked into the walking bracket. This is a very troublesome thing. Fortunately, I drive my own excavator and don’t have to listen to the boss’s roaring complaints. But the price I paid was: a set of clothes including shoes, a day’s time, and ten barrels of 18 liters of hydraulic oil.
There is another very scary and dangerous situation that few people have encountered, unless you are as unlucky as me, that is, the excavator cannot stop moving. As we all know, the operating handle of the excavator is an action in each direction. When the handle is in the middle position, the excavator will not move. But if the handle is in the middle position, the excavator will continue to move. Can you imagine how scary this is? Why does this phenomenon occur?
The reason why I encountered this situation is that a large amount of iron powder appeared in the hydraulic oil of the entire hydraulic system, causing the pilot switch (commonly known as the bullet head) to be stuck, or the small filter at the pilot switch to be blocked. And a large amount of iron powder in the hydraulic oil is from the travel reduction box to the hydraulic system.
There are also various symptoms of "mechanical cold", such as high engine water temperature, weak machine, and bubbles in the auxiliary water tank, that is, the cylinder mattress is flushed, which is a small problem, but if it is not handled, it will immediately cause big trouble. So we also need to observe more when we work, and prescribe the right medicine for various symptoms.
Choose BONOVO for high-quality, customizable brush cutters for skid steers with fast delivery. Contact us today to discover how our superior products can enhance your land management tasks!
for more info just visit our website at www.bonovogroup.com
contact # : +86 158 6218 2088
email : sales@bonovogroup.com