I drove across town one day and there was a little puddle under the truck, I drove it home... no puddle. Drove it across town it heated up really quick but didn't get hot. Added some water to the overflow tank just incase the radator was low (I didn't want to take the cap off). Headed over and bought a bottle of the radiator stop leak copper stuff. Park it home for a few hours, pop the rad cap off and its still completely FULL. I pump some out and dump in the bottle of copper sealer stuff and topped off the radiator. Started the truck up for 20minutes, heated up to 195 and stayed there, jumped in drove around, got home no more leaks. Drove to Indy (about 55miles) and when I parked it there was a few drops of collant on the shroud and it steamed but no puddles. Drove it home 55miles, no smoke no puddles, just a little collant on the shroud. Have driven it across town and back several times and no more steam or puddles... /forums/images/graemlins/confused.gif /forums/images/graemlins/dunno.gif BUT its still completely full and the overflow tank is down maybe 1/2" /forums/images/graemlins/thinking.gif SO did it seal up? its in my 87 daily driver, the radiator looks a little crusty inside (I flushed it with prestone cooler/cleaner about two years ago), but the coolant is still BRIGHT green still (with little copper flakes). Question 2 - should I just buy another radiator and replace it, then take the questionable radiator to the shop have them clean it out and pressurize it and try to fix the leak... once I get it back I can install it in my project rig in place of the green crusty radiator in it... then have that radiator cleaned and checked then hold on to it as a backup?