Check the voltage at the motor terminals while operating (with a clean filter, all valves open etc. - you want the minimum restriction to flow for this test). If the voltage is low, that could cause higher than normal operating temperatures. However, 180 degrees sounds acceptable. You can also reduce the load on the pump by partially closing valves on the discharge lines. This increases the pump pressure, but decreases the flow rate which (counter-intuitively) decreases the load on the motor.