Generally, synthetics and semi-synthetics, made with surfactants, by their nature will tend to foam a little. The key is to pay attention to the dilution ratio.
Too much lubricoolant in the dilution ratio will produce a foaming issue. Reduce the ratio of lubricoolant, and increase the ratio of water.
If there is not enough lubricoolant in the sump, your pump can have a tendency to cavitate, producing major foam issue. Make sure pump doesn’t cavitate by increasing the amount of fluid in the sump.
If your flood coolant lines are small, and you have a powerful pump, that can create foaming. See if you can increase size of the lines.
If all of these steps have been tried and you still have a foaming issue, you may be using the wrong lubricoolant for the specific job at hand, please contact us.