Location:
The heater core is located inside the dashboard, behind the instrument panel. This means you'll have to disassemble a large portion of the interior to access it.
Removal and Replacement Process (General Overview):
This is a highly simplified overview. You will need a detailed repair manual specific to your 1978 Chevy Nova to guide you through the precise steps and torque specifications. A Haynes or Chilton manual is a good investment for this type of repair.
1. Disconnect the Battery: This is crucial for safety.
2. Drain the Coolant: Completely drain the engine's cooling system.
3. Interior Disassembly: This is the most labor-intensive part. You'll need to remove:
* Steering Wheel (Potentially): May need to be removed for access to the dashboard.
* Instrument Panel: This often involves removing screws, trim pieces, and potentially the steering column shroud.
* Dashboard Components: Radio, vents, glove box, etc., will need to be removed. Be careful to label and organize everything!
* Possibly the HVAC housing: You'll likely need to access and remove the heater case/housing to get to the core.
4. Accessing the Heater Core: Once you have the dashboard sufficiently disassembled, you'll locate the heater core within the HVAC housing. It's typically connected by rubber hoses and metal lines.
5. Disconnect the Hoses and Lines: Carefully disconnect the hoses and lines connected to the heater core. Have a catch pan ready to collect any remaining coolant.
6. Remove the Heater Core: The core itself is usually held in place by some sort of retaining clips or screws. Remove these carefully to extract the core.
7. Install the New Heater Core: Install the new heater core in the reverse order of removal, ensuring it's seated correctly.
8. Reconnect the Hoses and Lines: Reconnect the hoses and lines, ensuring a tight seal to prevent leaks.
9. Reassemble the Dashboard: Carefully reassemble the dashboard and all interior components. Double-check your work to make sure nothing is left loose or disconnected.
10. Refill and Bleed the Cooling System: Refill the cooling system with the correct coolant mixture. Bleed the system to remove any air pockets.
11. Test: Test the heater to ensure it's working correctly.
Important Considerations:
* Repair Manual: Absolutely essential. Pictures and diagrams will be invaluable.
* Patience: This is a time-consuming job.
* Organization: Keep track of all screws, bolts, and other parts as you remove them. Labeling is key.
* Special Tools: You may need special tools for removing certain interior components or accessing the heater core.
* Leak Testing: After reassembly, carefully check for any coolant leaks.
Professional Help: If you're not comfortable with this level of automotive repair, consider taking your car to a qualified mechanic. The cost of a professional repair might be less than the cost of damaging your car while attempting this yourself, especially if you lack experience. It's a difficult and complex job even for experienced mechanics.
