After the excavator has been working for a period of time, the cylinders of the large and small arms will be discolored, especially the older machines. The discoloration is more serious. Many people are not sure what is causing it, and think it is a quality problem of the cylinder.
The discoloration of the oil cylinder is a common phenomenon. There are many reasons, and most of the reasons for the discoloration have nothing to do with the quality of the cylinder. The following is a brief introduction to a Komatsu pc228 excavator that has been repaired recently by factory maintenance personnel. Let’s talk about the cause of the discoloration of the excavator cylinder and the solution.
Trouble phenomenon:
A customer’s Komatsu pc228 excavator, the oil cylinder of the machine changed color (the oil cylinder was black), and the hydraulic oil was changed by the company. It only took more than 500 hours. I don’t know what’s going on?
Failure analysis of discoloration of the excavator cylinder (black cylinder):
Generally, the color of the cylinder is changed.At first, the cylinder will appear blue, then the color will gradually darken and then turn into purple, until it finally becomes black.
In fact, the discoloration of the cylinder is not due to the chemical reaction itself, but the surface is covered with a colored film, so it looks like the cylinder is discolored. Let’s first analyze the reasons for the discoloration of the cylinder.
1. Large temperature difference between inside and outside of the cylinder
This situation often occurs in winter. After the excavator works for a long time, the temperature of the hydraulic system rises, and the temperature of the external environment is very low. At this time, there is a large temperature difference between the inside and the outside of the cylinder. The cylinder rod is in this situation. Down work can easily cause the cylinder to change color.
2. The quality of hydraulic oil is too poor
When replacing the hydraulic oil of an excavator, in order to save money, many bosses do not buy the original hydraulic oil, which can easily cause the cylinder to change color. Because the hydraulic oil will add an extreme pressure anti-wear additive, hydraulics of different manufacturers’ brands The ratio of additives in the oil is different, so mixing will cause discoloration and even affect the hydraulic system.
3. There are impurities on the surface of the cylinder rod
When the excavator is working, the cylinder rod of the hydraulic cylinder is often in contact with the external environment, and it is easy to adhere to dust and impurities, especially in harsh working conditions, which will be more serious. If it is not cleaned in time, the accumulation of dust and impurities will also cause the cylinder to change color .
If it turns blue, it may be caused by the additives in the oil seal and hydraulic oil adhering to the cylinder rod at high temperature. If it turns black, it may be that the lead contained in the spray in the wear sleeve is attached to the cylinder. The reason on the pole.
4. There are fine lines on the surface of the cylinder rod
There is another possibility that the quality of the cylinder rod is defective. The surface of the cylinder rod has cracks and fine lines that are difficult to find with the naked eye. The main reason is that the surface of the piston rod is not uniformly heated during the electroplating process, and the cracks will appear. The situation of the pattern. This situation is only found by a high-power magnifying glass.
After talking about the cause of the discoloration above, let’s talk about the solution to the discoloration of the excavator cylinder (the cylinder is black):
1.If you find that the surface of the cylinder has a small and small blue color, you can leave it alone.Usually, after a period of work, the blue color will automatically disappear.
2. If you find that the discoloration is very serious, you need to replace the new oil seal and wear sleeve, and check the hydraulic system at the same time to avoid the high temperature of the hydraulic oil. This situation usually disappears after a period of time.
3.If the front half of the bucket cylinder is discolored, it means that the temperature of the hydraulic oil is too high, and we need to clean the radiator comprehensively to reduce the temperature of the hydraulic oil during work.
4. If the cylinder is discolored after replacing the hydraulic oil of other brands, the original hydraulic oil should be replaced immediately at this time.
5. If the discoloration is caused by the cracking of the cylinder, this is the problem of the cylinder. If possible, coordinate with the manufacturer’s agent to solve it, or purchase a replacement cylinder by yourself.
In short, there are many reasons for the discoloration of the cylinder, some of which are caused by the external environment, and most of the main reasons are their own problems. For example, the quality of the hydraulic oil, the high temperature of the hydraulic oil, the quality of the cylinder, etc., in fact, these all require us to Some issues that need to be paid attention to in the daily maintenance process.
The discoloration of the cylinder is just a small warning that the hydraulic system is malfunctioning. Once you find that you can’t be paralyzed, you need to check the hydraulic system carefully and check the above aspects to check where the problem is. I believe that when you encounter similar failures in the future, you will know from What are the reasons? Let’s troubleshoot the problem!
In addition, our company supplies all kinds of excavator brand cylinders. If you need to replace the excavator cylinder, you can contact us at any time.
XCMG Vertical Cylinder Repair Kit
Komatsu PC200-8 excavator cylinder head cylinder assembly 6754-11-1101
Post time: Dec-20-2021