heater core replacement
Well you mentioned 'repair' heat core, better to replace. It's located on the passenger side behind the glove box. The whole dashboard needs to be removed, the A/C lines will need to be disconnected as well. So have a shop evacuate the system of refrigerant before you start. Put everything back together, add coolant, inspect your hoses while your at it and maybe replace, get the AC charged and your in business.
Search Toyota Corolla Questions
Toyota Corolla Experts