Scotty, help please.. used STEAL SEAL and now my heater core is clogged. only blows cool air. flushed 3 times as per your video but no success. Had to change tstat (hard metal pieces) and rad.. so ng

ONLY use such sealers in systems that are full of newer and clean coolant, or in pure water alone. And if car is really old, best to bypass the heater core when using the sealer, as old heater cores are already somewhat clogged up and any sealer can finish them off

oh no, 2007 camry and I always changed coolant every 3 years. Is there anything I can do.....