How to change the oil pump for melamine tableware molding machine?

www.melaminemouldingmachine.com
To serve more than 80 melamine tableware factories till now, the question to change the hydraulic pumps or pump core.
Engineer need to check the model of the pump first, and decide to replace the whole pump or only the pump core. Pump core is cheaper than the cost of complete set of pump.
But different pumps has different structure.
If you need to know more information, pls feel free to call :
Shelly [phone]