Here's a general overview of the process, but remember this is *not* a substitute for a proper repair manual:
1. Preparation:
* Safety First: Disconnect the battery's negative terminal.
* Gather Tools: You'll need various tools including screwdrivers (Phillips and flathead), wrenches (metric and possibly SAE), pliers, sockets, a drain pan, coolant recovery system, possibly a heater core flush tool, and potentially a specialized core removal tool depending on the access.
* Coolant Drain: Drain the engine's cooling system completely. Locate the drain plug on the engine block and radiator.
* Access: The process of accessing the heater core varies depending on whether your Nova has a separate heater box or an integrated unit. You'll likely need to remove parts of the dashboard, potentially the glove box, and possibly parts of the firewall. This is where a repair manual will be indispensable.
2. Removing the Old Heater Core:
* Disconnect Heater Hoses: Carefully disconnect the heater hoses from the core. Have rags ready to absorb spilled coolant.
* Remove the Heater Core Housing: This is where the difficulty lies. You'll likely need to remove the heater core housing itself, which involves unbolting it and carefully maneuvering it out, often requiring patience and finesse. This stage usually involves removing several interior components.
* Remove the Core: Once the housing is out, remove the old heater core. This can be challenging; it might be sealed with sealant or corrosion. A specialized core removal tool may be necessary.
3. Installing the New Heater Core:
* Clean the Housing: Thoroughly clean the heater core housing to remove any debris or corrosion.
* Install the New Core: Carefully install the new heater core into the housing, ensuring it sits correctly.
* Reassemble: Reassemble the heater core housing, securing all bolts and connections.
* Reconnect Heater Hoses: Reconnect the heater hoses to the new core.
4. Reassembly and Testing:
* Refill the Cooling System: Carefully refill the engine's cooling system with the correct type and amount of coolant.
* Bleed the System: Bleed the cooling system to remove any air pockets. This is crucial to prevent overheating.
* Test the Heater: Start the engine and test the heater. Look for leaks and ensure proper heating function.
Important Considerations:
* Corrosion: After 60 years, corrosion is a major concern. Expect rust and potential seized bolts. Penetrating oil may be your best friend.
* Seals and Gaskets: Replace all seals and gaskets while you're in there.
* Repair Manual: A repair manual specific to your 1963 Chevy II Nova is absolutely crucial. Pictures and diagrams are invaluable during this complex process.
This is a highly simplified overview. The actual process will be much more involved and challenging. Without detailed instructions from a repair manual specific to your vehicle, attempting this repair could lead to damage to your car. Consider seeking professional help if you're not comfortable with complex automotive repairs. The cost of professional labor may be less than the cost of parts and the frustration of a botched repair.
