simpson easyset 605?

i have a simpson easyset 605. the level switch stopped working. i was told to fill machine, take tube off vacuum switch, blow through it, crimp it to retain pressure in tube and then refit to switch. it then worked again but i have since removed it and refitted it while machine was empty and now it does not work. i cannot find any leaks. also the machine will not spin. does the vacuum switch play any part in activating the spin cycle once the pump has emptied the machine?