i have a 1999 gmc sierra 4.3 with air. i cant get the heater core out i have ripped half the dash out...........................help!!!!

 

First, Locate the access area for your particular heater core. Usually, the heater core is accessible by removing the plastic panels under the dash.Not sure with GMC Sierra parts but i think it may be similar to other models. Be careful not to move the heater core when removing the cover. You could damage it and cause a leak. Once you’ve accessed the heater core, pay attention to its location and how the pipes are positioned.Remove the heater core mounting clamps and any remaining hoses.With rags at the ready for any accidental spills, remove the heater core.Clean up any spills and, if needed, dry the carpeting with a blow dryer. Hope that helps. That's what I did with mine.