There is the following three points in the cylinder rod discoloration: 1. There is a high temperature phenomenon in the hydraulic system. During operation, the piston rod frequently contacts the low temperature environment under high temperature conditions (especially in the cold season). The temperature suddenly drops suddenly; 2, in the maintenance cycle, the hydraulic oil is not used for the brand excavator. This phenomenon usually shows the discoloration of the piston rod within a few days after the oil has been changed. The reason is that there is a difference in the quality and performance of the anti-wear additive in the hydraulic oil; 3. The uneven temperature control during the electroplating process of the piston rod causes cracks on the surface of the electroplated layer in the later work, and the surface of the piston rod is observed with a high magnification magnifying glass. Irregular small cracks can be seen.

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