[Xist]

It looks like AutoZone took down their repair library and replaced it with five minute crafts, but Google has the cache. For posterity, it is:


1996-97 Civic and Del Sol
Removing the heater core may require removal of the dashboard and the air conditioner evaporator. Removal of the air conditioner evaporator requires the A/C system to be discharged. The legal ramifications of discharging A/C systems without the proper EPA certification, experience, and equipment dictate that the A/C components on your vehicle should be serviced only by a Motor Vehicle Air Conditioning (MVAC) trained, and EPA certified automotive technician using approved equipment.

If you insist upon servicing the heater core and you are not a Motor Vehicle Air Conditioning (MVAC) trained, and EPA certified automotive technician and/or you do have the approved equipment for discharging and recovery of the A/C refrigerant, before disabling your vehicle, take your vehicle to an approved repair facility and have the A/C system discharged prior to beginning the heater core repair procedure.

1. Take your vehicle to an approved repair facility and have the A/C system discharged.
2. Record your vehicles radio anti-theft code.
3. Disconnect the negative battery cable.
4. From under the hood, locate the heater control valve on the lower passenger's side firewall area just below the fuel filter. Manually turn the heater control valve to the opened position.
5. Make sure the heater valve is in the full hot position by pressing the arm toward the firewall.
6. Allow the engine to cool if the coolant temperature is above 100°F (37°C).
7. Drain the engine coolant from the radiator into a suitable and sealable container.
8. Remove the heater control valve.
9. Place a drain pan below the two heater hoses at the firewall, release the tension on both heater hose clamps and slide the clamps up the heater hose away from the firewall and remove the two hoses.
   
   
10. Drain the coolant from the hoses into the drain pan and then into a suitable and sealable container.
11. Remove the nut attached to the stud protruding through the firewall, just above and to the right of the heater hoses.
    
12. Remove the dashboard assembly.
    On del Sol models, remove the steering hanger beam bolts.
    
    
    
13. Remove the heater duct.
14. Detach the heater unit from the firewall.
15. Remove the self-tapping screws and the bracket.
16. Pull the heater core out of the housing.
    To install:
    
    The installation procedure is in reverse order of disassembly making note of the following points.
17. For the air conditioning system:
    • Replace any removed A/C O-rings and coat them with a light coating of refrigerant oil before installing them.
    • Make sure any replaced O-rings are compatible with R-134a refrigerant.
    • Once the repair procedure is completed, have a certified repair facility add the proper type and amount of refrigerant oil if necessary, charge the A/C system, and test for normal operation and refrigerant leaks.
18. For the heater system:
    • Apply a suitable sealant to the grommets.
    • Make sure the heater inlet and outlet hoses are installed in the correct location.
    • Refill the engine coolant with a 50/50 mixture of approved coolant and water, and bleed as necessary.
    • Once the heater core repair is completed, make sure the heater control valve is properly adjusted by placing the temperature setting to the max cool position. Unclamp the heater valve cable sheathing and move the heater valve arm away from the firewall. The apply a light pull to the cable and cable sheathing to make sure all slack is removed from the cable, and reinstall the cable.

1998-00 Civic
Removing the heater core may require removal of the dashboard and the air conditioner evaporator. Removal of the air conditioner evaporator requires the A/C system to be discharged. The legal ramifications of discharging A/C systems without the proper EPA certification, experience, and equipment dictate that the A/C components on your vehicle should be serviced only by a Motor Vehicle Air Conditioning (MVAC) trained, and EPA certified automotive technician using approved equipment.

If you insist upon servicing the heater core and you are not a Motor Vehicle Air Conditioning (MVAC) trained, and EPA certified automotive technician and/or you do have the approved equipment for discharging and recovery of the A/C refrigerant, before disabling your vehicle, take your vehicle to an approved repair facility and have the A/C system discharged prior to beginning the heater core repair procedure.

1. Take your vehicle to an approved repair facility and have the A/C system discharged.
2. Record your vehicles radio anti-theft code.
3. Disconnect the negative battery cable.
4. Under the hood, open the cable clamp, disconnect the heater valve cable, and turn the heater valve arm to the fully opened position.
5. Drain the coolant. The engine must be cool.
6. Remove the mounting nut to the heater.
7. Push the hose clamps back.
8. Place a small drip pan under the heater hoses.
9. Remove the nut attached to the stud protruding through the firewall, just above and to the right of the heater hoses.
10. Remove the inlet and then the outlet hoses from the heater unit.
    
    Always keep engine coolant away from painted surfaces. If a spill does occur, rinse it off immediately. Never wipe it with a shop rag, this may further smear it into the surface.
11. Remove the mounting nut from the heater unit.
12. Remove the dashboard.
13. Remove the heater duct.
14. Detach the heater unit.
15. Remove the screws and then the bracket that holds the heater core in the air box.
    
    To install:
    
    The installation procedure is in reverse order of disassembly making note of the following points.
16. For the air conditioning system:
    • Replace any removed A/C O-rings and coat them with a light coating of refrigerant oil before installing them.
    • Make sure any replaced O-rings are compatible with R-134a refrigerant.
    • Once the repair procedure is completed, have a certified repair facility add the proper type and amount of refrigerant oil if necessary, charge the A/C system, and test for normal operation and refrigerant leaks.
17. For the heater system:
    • Apply a suitable sealant to the grommets.
    • Make sure the heater inlet and outlet hoses are installed in the correct location.
    • Refill the engine coolant with a 50/50 mixture of approved coolant and water, and bleed as necessary.
    • Once the heater core repair is completed, make sure the heater control valve is properly adjusted by placing the temperature setting to the max cool position. Unclamp the heater valve cable sheathing and move the heater valve arm away from the firewall. The apply a light pull to the cable and cable sheathing to make sure all slack is removed from the cable, and reinstall the cable.

Wonderful. I lost all of my directions and spent my available time preserving AutoZone's. So far the only thing that I have noticed that AutoZone specified that Honda did not was to evacuate the refrigerant first. I have not seen that step in the FSM yet.

It is pretty important!