Worked for 7-months at a Cat dealer repairing radiators and heat exchangers (bad, bad, experience). We used caustic soda to boil out the nasty stuff. 9 times out of 10 we installed a new core or we popped the tanks and rodded out the tubes individually. They are actually simple to repair but you need the right equipment to do it well. You did the right thing taking it to a shop. Just as a side note I bought a brand new U.S. made radiator from LMC for $240
