Dripping Tap syndrome

I have a dripping heads tap on my First 31.7, it's brand new..and peforms just as well as the one I replaced.... ie it DRIPS !!

That in its self is kind of ok but not when it kicks in the pump.... is this a commomn problem with the plastimo fitting, it doesn't look as if the unit comes apart to replace any washers.... does anyone have any thoughts.

John