i am having problems with my motor not running on high speed the low speed works fine but when i switch it to high it makes a loud hum and vibration and pumps slowly everything else works fine

Could be wired incorrectly (L1 and Low wires reversed on the pump), inadequate voltage, or you could have a bad high speed capacitor in the motor, or even bad bearings.

It also could be a control issue and the low speed relay is stuck closed (or miswired) so when you go to high speed it still is trying to run low.

High and low at the same time make a loud hum noise and will heat the motor quite fast. If this is the problem the motor will hum for a few seconds and then the thermal breaker in the motor will shut it down.