Here's a general overview of the process. This is not a complete guide and should be supplemented with a repair manual:
1. Preparation:
* Disconnect the Battery: This is crucial to prevent electrical shorts.
* Gather Tools: You'll need various tools, including sockets, wrenches (metric and standard), screwdrivers, pliers, a coolant recovery system, possibly a hose clamp pliers, and potentially a sealant for the hoses. A shop manual will list specific tools.
* Drain the Coolant: Completely drain the cooling system. This involves opening the radiator drain valve and possibly a block drain plug. Dispose of the coolant properly.
* Gather Supplies: Obtain a new heater core, new hoses (if needed), and new coolant.
2. Accessing the Heater Core:
* Dash Removal (Most Likely): This is the most challenging part. You'll likely need to partially or completely remove the dashboard to access the heater core. This involves removing various screws, nuts, and possibly the steering column. The process is highly dependent on the specific model and options your Impala has. Your repair manual is critical here.
* Other Access Points (Possibly): Depending on your Impala's configuration, there might be other access points, but dash removal is most likely.
3. Heater Core Removal:
* Disconnect Hoses: Carefully disconnect the hoses leading to and from the heater core. Have rags ready to absorb spilled coolant.
* Remove the Heater Core: Once the hoses are disconnected, carefully remove the heater core from its housing. This may involve removing retaining clips, screws, or other fasteners. Again, your repair manual will guide you.
4. Heater Core Installation:
* Install the New Heater Core: Carefully install the new heater core into its housing, ensuring it's properly seated.
* Reconnect Hoses: Reconnect the hoses to the new heater core, ensuring a tight seal. Use new hose clamps if necessary.
* Reinstall Components: Carefully reinstall all components that were removed to access the heater core, working in reverse order of removal.
5. System Reassembly and Testing:
* Refill the Cooling System: Refill the cooling system with the correct coolant mixture. Refer to your owner's manual or a coolant supplier for the proper mixture.
* Bleed the System: Carefully bleed the cooling system to remove any air pockets. This is crucial to prevent overheating. Your repair manual will explain how to properly bleed the system.
* Test for Leaks: Start the engine and check for leaks around the heater core and hoses.
* Check Heater Function: Once the engine reaches operating temperature, check the heater function to ensure it is working correctly.
Disclaimer: This is a simplified overview. Incorrect installation can lead to significant problems. Use a 1968 Chevy Impala-specific repair manual for detailed instructions and diagrams. If you are not comfortable with this level of auto repair, it's best to take your vehicle to a qualified mechanic. This job is significantly more difficult than it appears.
