Unloading at 20bar pressure is always above, this may be due to the three-way flow valve is fully open, check-way flow valve spool movement is flexible (variable pump) maintenance, if necessary, replace the valve, including the damping; systems The pressure is always reach the predetermined value, the leakage may be three-way flow control valve is too large. Then we must replace three-way flow control valve piston or connecting blocks. Low low speed test run: Repeat start and shut down the motor variable pump, the pump and the suction air release. Ten percent of the input pressure and flow, open radio station forward and backward motion (variable pump) Training for flow and pressure valve exhaust. Running ten minutes later, as the hydraulic system no abnormal sound, you can boot. If you stop using the machine again after a period of use should also do so to boot. (Variable pump) repair, variable pump, hydraulic pressure from Jinan Jing Jing Chong Chong Hydraulic Machinery Limited. Jinan Jing Chong Hydraulic Machinery Co., Ltd. (www.jnjcyy.com) (www.jnjcyy.com) strong, credible, in Jinan, Shandong mining machinery industry has accumulated a large number of loyal customers. The company better work attitude and continuous improvement to create innovative ideas will lead crystal hydraulic and you hand into the brilliant, for a better future!