hi i have a stuart and turner, monsoon, negetive head ,twin impeller pump
which runs the water ok but when not running is making a load noise,it sounds like it is trying to start,there is a cylinder on the pump which has a filling loop to it and on the top is a valve that looks like a inner tube valve for air i pressed the valve and nothing came out from it,is this supposed to be gassed up or just filled with air,i was thinking maybe that is the problem with it,althought the pumpis quiet a few years old now.any idea anyone please