The XE135B hydraulic excavator subject to full hydraulic drive has been widely used throughout China and exported to more than twenty countries and regions in the world by virtue of its high working efficiency like medium-sized e xcavators and such characteristics of less fuel consumption and higher flexibility for small-sized excavators. Its working mechanism has a high-strength structure, able to meet the demands of all kinds of earthwork engineering if working together with a reinforced bucket; the latest hydraulic components and electromechanical integration control technology can make full use of the engine power and save every drop of fuel to create more value for customers; its high-power driving motor can work freely in a variety of sites; all kinds of points for daily maintenance and service can be accessible easily on the ground, which can further facilitate the maintenance operation.