Leaking coolant

1991 Honda Accord LX (5 spd stick) - Hit dog, replaced radiator - before replacing used radiator stop leak (black pellet type). After replacing, everything fine for about 1-2 wks. Then idle started reving up & down at start & temp gauge goes up after about 10 min of operation. Heat will not work initially but kicks in after about 10-15 mins. - Chk fluid level = empty or close to it, fill up & all is fine for about 2 days max. No visible leaks while running but after shut down there is a big puddle under drivers side, just inside of wheel. Serviced up fluid yesterday, started & put up on lift for 20-25 min. = No visible leaking? Shut down, left on lift overnight - this morning fluid everywhere under drivers front - just inside wheel. Found where leaking - just above CV axle there is an elongated silver housing with a black plastic cover on left side (wheel side) that has a belt & pulleys running on the left of that (towards wheel) - fluid is steadily dripping out of a small hole on the edge of that silver housing. It looks like maybe a plug should be there or maybe it's threaded for a bolt but there is fluid coming out of that hole? I'm assuming this is the water pump? Have NO idea why fluid is coming out there or how to fix? PLEASE help.