as most of the Populace in the Northern Hemisphere already know; Winter is coming soon, and everyone needs to check up on their Coolant! I did that today, and I discovered why the Coolant in Scoots' Expansion Bottle was Disappearing! just for Kicks and Grins, I borrowed my School's Cooling System Pressure Tester not to Test the Cap (because its Virtually Brand New), but the Actual System itself; and what I discovered was VERY disheartening: I pressurized the system to its usual 17 PSI (that would be 1.1 bar/117.2 KPa for you International Types) and looked underneath to see the telltale Drip of precious Coolant falling onto the pavement. I looked a little closer, to find it was coming from between the Water Pump and its Volute! (I don't think the water pump itself is faulty, because I noticed moisture seeping from the top seam as well) and from what I've read, its an RTV Silicone seal that forms the water pump gasket. so my advice is to check your Water Pump Gaskets!