Heater Core

Hi,

If the A/C is charged with refrigerant you'll have to have that recovered before disconnecting the A/C lines. When you do disconnect the lines plug or cap both the open hose ends and evaporator side of things to prevent dirt from entering. This is really important as it doesn't take much to mess up the expansion valve. Also, if the A/C system has been empty and you want to convert from R-12 to R-134A this would be a great opportunity to flush the evaporator core.