The hydraulic cylinder of hydraulic excavator consists of three main parts: boom cylinder, bucket cylinder and bucket cylinder, and four cylinders. Because each cylinder has direct control of its working device, it frequently realizes its movement in a large thrust range, and most of them have no outer protective device, so the failure rate is high in the whole hydraulic system. 

Different parts oil cylinder seal is not the same, mainly including the grill ring, O seal ring, the size of the dust ring are different, it is recommended that you do well is the size of the car, the oil seal of that part.