Or just buy the "Golden Seal" version which comes in powdered form...
The comment to add the stuff to the lower radiator hose is quite valid for Cadillac's Northstar engines. Not so much for the 4.1 4.5 and 4.9. That is because Northstar doesn't have a radiator cap in the radiator - only in the overflow tank. If you wan't to see exactly why, search the Northstar forum for more info.
But if you have the hoses off, adding it to the lower hose won't hurt anything. I prefer the powdered stuff. Or, you could take some antifreeze, dissolve the tablets in it, then pour the mud into the radiator!
Peteski
