Leaking water somewhere

What is your question?

I just recently had the radiator and thermostat replaced but now I am leaking water from somewhere. I have tied a rag around cap and it doesn't leak. Put card board underneath van and found no leaks. I have also checked my oil to see if it is cloudy and it is in good shape. I will let it run during these checks(except for checking oil). I don't know where else to look. I can drive 5 miles down the road, come back, let it cool and then check it. At that time it is low on water.