Antifreeze/water leakage

[JRS]

about 5,000 miles ago I replaced the thermostat, water pump, heater hoses, both the small bypass hoses at the front of the engine, and the upper and lower radiator hoses all under the guise of preventative maint. A week ago I started losing coolant, not a lot, but maybe a 1/8"-1/4" every two or three days out of the resevoir. (I drive about the same mileage every day) I check the weep hole on the water pump everday, both when it's cold and when it's hot and pressured up, and nothing. I can't see any evidence of leaking anywhere else. I have checked the heater hoses where they pass through the fire wall, both ends of the radiator hoses, the small bypass hoses, and the passenger floorboard. All are bone dry, both when the engine is cold and when it's hot and pressured up. I can't smell any antifreeze burning (like from a leak getting on a hot manifold or engine) When I installed the water pump I made sure the mating surfaces were hospital clean by prepping the surfaces with a 3-M scotch-brite pad on my die grinder, then wiping them down with a rag and some brake cleaner. I then coated the rubber gasket with a THIN layer of high-temp silicone, let it get tacky for 15 minutes, then installed the water pump and torqued the bolts to the final torque. Is this the correct procedure for installing the pump? should I use any silicone on the rubber gasket? Any other ideas?