anti freeze dripping

I have a 94 k1500 with a 5.7 liter engine. There is Anti freeze dripping out of a elbow where the heater hoses go into the firewall. What does this mean? The truck has been doing this alot lately, especially when the heater has been running. Do I have a leaking heater core? And what is the function of that elbow. Any insight would be helpful.
Thanks,
No2ski

Most likely the heater core is leaking.
The elbow is to direct the condensation buildup towards the outside of the heater case.