Tools and Materials Needed:
- Replacement Heater Core
- Coolant
- Antifreeze
- Socket wrench set
- Phillips head screwdriver
- Flat head screwdriver
- Pliers
- Safety goggles
- Gloves
- Towels
- Container for draining coolant
Step 1: Safety Preparations
- Park the vehicle on a level surface and allow the engine to cool down completely.
- Disconnect the negative terminal of the battery to prevent any electrical issues during the repair.
Step 2: Drain Coolant
- Locate the drain petcock on the radiator or engine block. Place the container under the drain petcock and open it to drain the coolant from the vehicle.
- Once the coolant is drained, close the drain petcock.
Step 3: Access the Heater Core Box
- Go inside the vehicle and remove the center console to access the heater core box.
- You may also need to remove the glove compartment to get better access.
Step 4: Disconnect Hoses
- Locate the heater core hoses connected to the heater core box.
- Loosen the hose clamps and carefully disconnect the hoses. Allow any residual coolant to drain.
Step 5: Remove Heater Core Box Cover
- Remove the screws or bolts that hold the heater core box cover in place.
- Carefully lift the cover to expose the heater core.
Step 6: Remove Old Heater Core
- Gently remove the old heater core from the housing. Be mindful of any debris that may fall into the ventilation system.
Step 7: Replace with New Heater Core
- Position the new heater core into the housing. Make sure it's properly seated.
Step 8: Reattach Hoses
- Reconnect the heater core hoses to their respective ports on the heater core. Secure them with the hose clamps.
Step 9: Replace Heater Core Box Cover
- Reinstall the heater core box cover and secure it with the screws or bolts you removed earlier.
Step 10: Refill Coolant
- Locate the coolant reservoir or expansion tank.
- Mix the coolant with water according to the manufacturer's recommendations. Usually, a 50/50 mix is recommended.
- Fill the coolant reservoir with the coolant mixture until the level reaches the "full" mark.
Step 11: Bleed the Cooling System
- Start the engine and let it idle for a few minutes with the heater set to high.
- As the engine warms up, squeeze the upper and lower radiator hoses to help expel any trapped air from the cooling system.
- Continue bleeding the system until no more bubbles appear.
Step 12: Reconnect Battery
- Reconnect the negative terminal of the battery.
Step 13: Test the Heater
- Turn on the heater and make sure warm air is blowing through the vents.
Note: The steps provided are general guidelines and the actual process may vary slightly depending on your specific model and year of Cadillac Seville. If you're not confident in performing this repair yourself, it's best to consult with a professional mechanic.
