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

In fact, in many cases, the discoloration of the oil cylinder has nothing to do with its quality. Next, the editor will explain the reasons for the discoloration of the oil cylinder and the treatment methods.

The phenomenon that the oil cylinder turns black, blue or purple is not the discoloration of the oil cylinder itself, but the surface of the oil cylinder is covered with a colored film, so it is not the problem of the oil cylinder itself.

Typically, the cylinder will first turn blue, then darken, turn purple, and finally black.

There are many reasons for the discoloration of the oil cylinder. The following are the common discoloration reasons.

1. There is a high temperature phenomenon in the hydraulic system, and the piston rod is frequently in contact with the low temperature environment under high temperature (especially in the cold season) during work (the temperature drops suddenly);

2. During the maintenance cycle, the hydraulic oil for excavators other than this brand is replaced, and the discoloration of the piston rod generally occurs within a few days after the oil is replaced. The reason is that the quality and performance of an extreme pressure anti-wear additive in hydraulic oil are different;

3. The blueness of the oil cylinder is caused by the additives in the oil seal and hydraulic oil adhering to the oil cylinder rod at high temperature, and the blackening is caused by the lead-containing additives in the spray material in the cup (ie the wear-resistant sleeve) adhering to the oil cylinder at high temperature. on the rod. Generally, the hydraulic oil temperature is too high, and this phenomenon mostly occurs in the first half of the bucket cylinders that are used more. We recommend that the dust and soil of the radiator be cleaned frequently to ensure the heat dissipation effect.

Methods to deal with the problem of discoloration of the oil cylinder:

If there is a very slight blue color in the oil cylinder, you can ignore it, it will disappear automatically after a period of time;

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