Hello, this is what we do, but it's a new machine. According to personal experience, it is estimated that the commonly used machine depends on whether the motor, oil cylinder and sealing ring leak oil. And other steel products can be seen clearly. Used ones are most afraid of no pressure, oil cylinder and motor problems. If there is oil leakage, replace the sealing ring. It doesn't matter at the facet joints. It is estimated that the cylinder can only be replaced by the manufacturer, but I don't have that experience. More troublesome. Personal experience for reference.