Ok, so about 1 1/2 months ago my brother told us we needed our water pump replaced cause it was leaking. The overflow tank never seemed to hold fluid. We have a friend who replace our water pump and thermostat. Wow, it did make a difference in the heat that came from our heater. What brought all this on was, I was smelling antifreeze ever time the suburban was ran. Well, I'm still smelling this smell but the radiator isn't losing any fluid. So it seems fine, however the overflow tank isn't holding any fluid we add. Could we just have a crack in the over flow and the leaking fluid is burning on the engine/belts and causing the smell? We have no leaks under the dash. We can add a mixture to the overflow every two days? I'm pretty inclinded to fix certain things and the overflow tank seems like an easy fix but I don't want to tackle it, if there could be something more wrong. The vehicle never has smoked or overheated either.
Any information, suggestions would be greatly appreciated.

Thanks Everyone