Will your excavator oil cylinder change color or leak oil?


Posted March 22, 2023 by HUITONG

Many excavator users have encountered the problem of oil cylinder discoloration, thinking that there is a problem with the quality of the oil cylinder, and are often anxious.

 
Many excavator users have encountered the problem of oil cylinder discoloration, thinking that there is a problem with the quality of the oil cylinder, and are often anxious. In fact, discoloration of excavator oil cylinder is a very common phenomenon.

Recognition skills such as: Under normal circumstances, the oil tank will first turn blue, then the color will deepen, turn purple, and finally black.

The discoloration of the excavator oil cylinder is not the discoloration of the cylinder itself
The phenomenon that the excavator oil cylinder turns black, blue or purple is actually a layer of colored film on the surface of the oil cylinder, not the problem of the oil cylinder itself. Normally, the cylinder will first turn blue, then darken, turn purple, and finally black.

There are many reasons for the discoloration of the excavator cylinder:
1.There is a high temperature phenomenon in the hydraulic system. During work, the piston rod is in high temperature state (especially in the cold season) and frequently contacts with the low temperature environment (the temperature drops suddenly);

2.During the maintenance cycle, the special hydraulic oil for excavators other than this brand is replaced. This phenomenon usually occurs within a few days after the oil is changed. Discoloration of the piston rod. The reason is that there is an extreme pressure anti-wear additive in the hydraulic oil that has different quality and performance;

3.Due to uneven temperature control during the electroplating process of the piston rod, cracks appear on the surface of the electroplating layer in the later work. Observing the surface of the piston rod with a high-magnification magnifying glass can see irregular and small cracks.

4.The blue is caused by the additives in the oil seal and hydraulic oil attached to the cylinder rod at high temperature, and the black is caused by the lead-containing additive in the spray in the cup (that is, the wear-resistant sleeve) attached to the cylinder rod at high temperature.

Generally, it is caused by the high temperature of the hydraulic oil, and this phenomenon mostly occurs in the first half of the bucket oil cylinder that is used more. It is recommended to clean the dust on the radiator part frequently to ensure the heat dissipation effect.

How to deal with the discoloration of the excavator cylinder?
If there is a very small part of blue in the cylinder, you can ignore it, and it will disappear automatically after a while;

If the discoloration is serious, the oil seal and wear-resistant sleeve need to be replaced, and at the same time try to avoid high temperature of the hydraulic oil, and it will return to normal after a period of time.

The problem of oil leakage in the oil cylinder
External leakage
1.The seal damage between the extending end of the piston rod and the piston rod is mostly caused by the roughening of the piston cylinder, and it is also caused by aging.

2.The seal between the extending end of the piston rod and the cylinder liner is damaged. This is mostly caused by the aging of the seal. There are also many cases where the seal is squeezed and damaged by excessive force when the upper end cover is used. In addition, many domestic manufacturers of hydraulic cylinders have poor design. Reasonably caused, in most cases, manufacturers are caused to save costs.

3.Cracking of the inlet and outlet oil pipe joints of the oil cylinder will also cause leakage of the hydraulic oil cylinder.

4.Oil leakage caused by defects on the cylinder block or cylinder end cover.

5.The piston rod is pulled and has grooves, pits, etc.

6.The deterioration of the lubricating oil makes the temperature of the oil cylinder rise abnormally, which promotes the aging of the sealing ring.

7.Oil leakage caused by frequent use beyond the pressure range of the cylinder.

Internal leakage

1.The wear-resistant ring on the piston is severely worn, causing friction between the piston and the cylinder liner, and finally straining the cylinder liner, piston and seal.

2.The seal fails after long-term use, and the piston seal (mostly U, V, Y-rings, etc.) is aging.

3.The hydraulic oil is dirty, and a large amount of impurities enter the cylinder and wear the piston seal to the point of damage, usually iron filings or other foreign matter.
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Issued By HITE Machinery
Phone 18922117251
Business Address No.1 Qiangang Street, Jinpen Industrial Park, Baiyun District, Guangzhou, Gunagdong, China
Country China
Categories Construction , Industry , Manufacturing
Tags excavator oil cylinder , excavatorcylinder , excavator hydraulic cylinder
Last Updated March 22, 2023