Each action of the front accessories of the excavator is realized by the oil cylinder. In the frequent reciprocating movement,the cylinder is susceptible to the influence of oil quality and external factors. Discoloration of several precision piston rod surfaces may occur.
Why does colour-changing happens?
The hydraulic oil contains complex additives, under the action of specific temperature and hydraulic oil pressure, these additives will crystallized and attached to the surface of the precision piston rod. Then,under the action of shear force of hydraulic cylinder oil seal, the colour- changing happens. Different grades of hydraulic oil should not be mixed, otherwise the quality of the oil will go down, in severe cases, the oil will go bad. Hydraulic oil contains a variety of additives with specific functions. When the oil that has different systems of additives is mixed, the performance of insulation materials will be affected, even the additives may settle and go bad. The piston rods can also be coloured in this case.
How to deal with the colour-changing
Colour-changing is a kind of individual occasional phenomenon,the hydraulic cylinder still can be trusted to use. The temperature and pressure of hydraulic oil in each cylinder are different, the clearances between the seals for hydraulic cylinder and the piston rods are also different, even the piston rods are on the same excavator. Therefore the colour-changing may occasionally appears on individual products. While this phenomenon will not affect its performance, nor will it lead to the shortening of its service life.
