1) Selected cleaning oil: the pipeline oil tank of the hydraulic press system is relatively clean, and the viscosity of the working fluid or the same kind of cleaning oil can be used. If it is found that the system is not clean, the cleaning may be slightly low viscosity oil.  
2) Heating oil cleaning: the accessories of the hot oil system of the hydraulic press are easy to fall off, and are usually heated to 50-60 ℃. When the cleaning pressure is 0.2-0.4mpa, the flow rate of the clean oil is as large as possible to facilitate dirt removal.  
3) Installed filter: 50-100 μ In the cleaning circuit of the primary filter, the inlet is installed and the oil return port is 10-50 μ Filter installation. At the beginning of the coarse efficiency filter, after flushing for a period of time, gradually switch to the fine grid oil filter and gradient filter. The cleaning time is generally 8 to 24 hours. Open the hydraulic oil filter of the machine every half an hour, and gradually replace the fine mesh filter and the role of washing. Good low viscosity oil, prolong the cleaning time interval, clean the hydraulic machine with serious pollution, reuse and clean the viscosity of the oil to be cleaned, and use similar oil.  
4) Knocking with a wooden hammer on the clean side can promote the removal rate of pollutants. Bend and welding parts are percussion instruments, but do not use excessive force to avoid the deformation and fracture of the hydraulic press pipe.  
5) Discharge cleaning oil: after the cleaning of the hydraulic press, drain the cleaning oil as much as possible, including the cleaning oil accumulated in the pump, valve, pipeline and cooler. Loosen the pipe, purge with compressed air, or add working oil and take away the cleaning oil. 6) Add a new hydraulic working oil, clean the oil and drain it. Add a new hydraulic oil immediately and run the test for a short time to prevent hydraulic press pipe corrosion and other adverse effects.