Originally posted by ThunderBat:
coolant will leakout of the weep hole on the bottom of the water pump shaft and be slung by the spinning pulley. When the engine is off and cool (not under pressure) it can go almost un-noticed. My wife's Montana minivan leaked like that for weeks before I finally nailed it down.
Yep, the dreaded weep hole. If you have a small mirror handy you can usually spot it leaking, but it may be harder to see it, with the water pump pulley in the way.
Tbat, my '66 Riviera once decided it needed a water pump, on the way to cruise night. Luckily I spotted the leak in the driveway, before heading out. Already had a new pump put aside, ready to install. Had it swapped in about 20 minutes!