Radiator flush question(again)

[BExplorer]

After reading the old posts on the subject, I still have question. I need to change the termostat(bought one yesterday) but also need to flush coolant(over 3 years old) and last year I poured in a sealant kit. Since I need to change the rad anyway, do I do a flush before/in the process/after the rad change, I know my new rad is going to be clean but I'm woried that the sealant stuff will sit in the engine(as for the overflow tank it is half full of that brown stuff, I will clean the tank). To clean the engine and water pump do I need to run the engine or can I just discard my old rad and fill engine with water until it comes out clean(sort of) then put the new rad and fill to spec with coolant???????

 

[RTStork]

I would flush the engine while the old radiator is still in there. If youwait and flush the engine after you installed the new radiator, you may get some crap in your new radiator. Just my opinion.

 

[DesertSpive]

Definately do a flush with the old radiator in, you might even want to do another flush with water after you install the new one.

--Sean