Originally Posted by vital49
Your radiator might be cracked. It could be such a small crack that it only swells when hot.
You are absolutely correct. It only leaks when the coolant is very hot (I'm not talking operating temp hot where the Tstat is open and the upper rad hose is hot, but after driving for a little while).
John Deere Boy, how long does it take the Super Leak sealer to work in? I've city driven about 15 minutes twice a day for the last two days. I also ran it for 20 minutes while parked as the instructions said.
I won't put any more in now.