replacing heater core on a 72 with integral AC

[tkelley]

I'm looking for some tips on a project that I have heard is a real bear! I have a 72 with the deluxe interior, console and center instrument panel guage cluster and integral AC. Exactly what has to be removed in order to get the heater core out? From what I have read in the past it may involve everything but the steering wheel removal. I'm replacing the center guage panel anyway (just purchased a new aftermarket one that is an exact replica of the original). Any help would be appreciated. Thanks

[Mach 1 Club]

71-3 Heater Core Removal

1. Disconnect Heater and AC hoses. (See manual on proper AC disconnection procedures.)

2. Cut drain hose from under car at bottom of firewall. You may want to save the plug that’s inside the end of the drain hose, which is there to prevent critters from entering your heater box. Note: If you bypass this step, you will likely break the fiberglass drain nipple off your heater box trying to pull it out.

3. Remove glove box door and glove box insert.

4. If you have a camera, take a picture of the vacuum hose and temperature control cable area now before disassembly. Label hoses to further aid in reassembly.

5. Disconnect: Thermostat switch wires; vacuum hoses to heater box (2) vacuum canisters; vacuum hoses to (cable controlled) water valve switch; and cable to water valve switch.

6. On the engine side of the firewall, remove 2 heater box hex/washer nuts. Easily identified by large washer and long protruding studs.

7. Remove 2 blower motor housing retaining screws (under dash center) and permit blower housing to hang (no need to remove the firewall mounting on the blower motor).

8. You may need to remove the vacuum canisters to give the heater box assembly some wiggle room during removal and installation.

9. Remove the heater box to cowl retaining screw (look up at right side of heater box).

10. Remove heater box assembly by sliding to the right (to disengage the blower fan), then down.

11. On the removed heater box, put a large screwdriver blade in the return of each metal spring clip such that you are opening up the springs to remove them. Do NOT pry the clips off by inserting the screwdriver under the clips – This will permanently damage the heater box.

Reverse to install.

Though some of the above is not included in the shop manual, if you need more info. (such as diagrams), I strongly recommend buying the full shop manual set.

[mrmach1]

Great instructions the only thing I would add is I prefer to remove the passengers seat just to give me room to move.

[Steven Harris]

Very true - seat removal (4 simple bolts) always saves a lot of neck and back pain.