before or after I replace the radiator/hoses/thermostat? thoughts?

 

before....no sense in cleaning new stuff with old fluid...

use the heavy duty flush and drive it and then flush it real good...I pill the hoses off the heater core and back flush it both ways until the water runs clean.

If the radiator is real crusty I will empty it and shake it dry best I can then fill it partially with CLR and let it set and slosh it around....then flush it but wear protective gear with the CLR...it will clean the rad nicely but burn you if it gets on you

 

What are your thoughts on running the CLR thru the same way you would the heavy duty flush? Would that help clean the radiator and heater core better?

 

I would pull the thermostat then flush it. Then there will be no restrictions.

 

it doesnt work at all if you pour it in with anti-freeze or dilute it with water. to be effective it needs to be full strength....

if I have one that really needs cleaned I pull it out and lay it flat and fill it with Muratic acid...that stuff cleans very well