Coolant leak at firewall near heater core...

Coolant appears to be leaking from a black rubber drain hose(?) coming through the firewall that I assume is coming from the heater core.
All I can see is dripping from the end of the rubber drain hose as I am viewing from the underside of the car. It's located next to two coolant lines that I assume feed the heater.
Help!!!
How should I repair the leak?
Thanks!

You will need to replace the heater core. This drain is designed to keep coolant out of the interior of the car if the core goes bad. You will need to disassemble the duct work under the dash to get to the core or take it to a shop to have it done. The heater core isn't real expensive but it is a time consuming job. PS. Don't drive it too far without checking on the coolant level. If the core breaks wide open you could loose all your coolant.

I too had a problem like this on my 2000 Grand Am GT. At the time, the car only had about 57,000 miles on it. The car leaked out about a liter of coolant from the drain tube coming from the heater core. I could never make the car leak coolant from the core again, however, every time I run my heater on high and then turn off my car, about 4-8 oz. of pure water comes out of the heater core drain tube just past the firewall(engine side). Is this normal, or could this be a sign of a bad heater core. Also, in a recent post of mine, it takes about 15 mins. for my heat to actually be warm in my car. Any input is apprectiated, thanx.