Failure in your Geo water pump can create a cascading effect that will seriously damage your engine and invoke major repair bills. The final sign of failure in a Geo water pump is repeated overheating of your engine. During a total engine overheating episode, the head gaskets will break or bend. That means hundreds, if not thousands of dollars in labor charges. So, take the time to diagnose your coolant system immediately when your Geo water pump begins to fail. A pressure test will determine if there is a leak in your water pump. It works by placing the pressure tester device where the radiator cap is located. If the completely closed system holds the pressure, than there is no leak to worry about. To trace the source of the leak, look for dripping coolant. You will see coolant dripping from the front of the pump or under the car. Even before that, you will see coolant fluid spots under your car after you have parked it for a while, Or, you will smell the strong odor of coolant while driving your Geo vehicle. If it's too hard to find, put ultraviolet sensitive dye in the coolant fluid, and then shine a black light over the engine to see the coolant liquid. If your water pump gasket is leaking, consider replacing your entire Geo water pump as well, as a preventative measure.