When the machine running, if dirt clogged pores balancing valve, leading to the parking brake can not be released, resulting in walking deviation. Because the machine variable pump care when walking., If not through the oil pressure balance valve orifice into the balancing valve spring chamber to promote balanced valve spool moves, the pressure balance valve oil can not pass through the slot on the system into its hydraulic , resulting in parking brake force can not be lifted, the results can not rotate the motor running, so there walking deviation. Remedy; cleaning Valves; when disassembly, to avoid dirt; regularly replaced to meet the requirements of hydraulic oil and filter. Maximum discharge displacement motor starting, when the working pressure is below the set pressure of the valve 7 variable pump maintenance., Valve 7 can not afford control action variable pump, the displacement of the motor with the pilot pressure at port X to changes infinitely variable between maximum and minimum, in order to achieve the pilot pressure control. When the motor A, B provide any work port pressure oil, the pressure oil can enter the small chamber 5 of the variable cylinder through the check valve. X port pilot control pressure increases, the pilot oil pressure acting on the valve a force to overcome the spring force regulator spring 2 and 3, to promote a move to the right valve, when the pilot pressure rises to the motor when starting variables When the pressure variable pump refinement., the valve will be in a neutral position. If the pilot pressure continues to rise, the servo valve will be further to the right, one in the left position servo valve function, motor working pressure oil through a valve into the variable cylinder 5 and 7 large cavity. Due to the variable area of ??the piston 6 is not equal at both ends, when both ends of the role of oil under pressure, variable piston moves to the left, fixed variable piston lever will drive the oil pan and cylinder swing, so the cylinder and the spindle angle decreases, so that the motor displacement is reduced. When X port control pressure is reduced, the motor control process with the above process is reversed, not repeat them here. In summary, when the pilot pressure to terminate the pressure change in the variable between the initial pressure and variable displacement motor will change accordingly between the maximum and minimum. Variable pump repair., Jing Chong hydraulic (certified), variable pump from Jinan Jing Chong hydraulic machinery Limited. Jinan Jing Chong Hydraulic Machinery Co., Ltd. (www.jnjcyy.com) (www.jnjcyy.com) Shandong Jinan, mining machinery leaders, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, the maximum meet customer needs. In the crystal to create a hydraulic leadership with the staff warmly welcome all inquiries negotiations to create the crystal to create a better future for the hydraulic.