replacing heater core on a 72 with integral AC
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
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.
Great instructions the only thing I would add is I prefer to remove the passengers seat just to give me room to move.
Very true - seat removal (4 simple bolts) always saves a lot of neck and back pain.

Forum Jump:

Users browsing this thread: 1 Guest(s)
Latest Threads
1969 Mustang Paint Codes & Colors
Last Post: jakeg
Today 11:24 AM
» Replies: 15
» Views: 13302
Throwback Picture
Last Post: Oztrailer
Yesterday 07:05 PM
» Replies: 2
» Views: 67
1973 Mach 1 parts
Last Post: Oztrailer
03-21-2019 07:39 PM
» Replies: 7
» Views: 1046
Will buy parts in real good condition or...
Last Post: shopcarpro
03-21-2019 10:39 AM
» Replies: 2
» Views: 191
Manual Trans Gear Oil
Last Post: JTS71 Mach1
03-21-2019 10:21 AM
» Replies: 11
» Views: 837
Need Data plate decode help pls.
Last Post: JTS71 Mach1
03-21-2019 10:17 AM
» Replies: 3
» Views: 147
My 1971 Mach 1
Last Post: Steven Harris
03-20-2019 02:25 PM
» Replies: 2
» Views: 196
Last Post: Mustangmike
03-07-2019 09:03 AM
» Replies: 69
» Views: 22934
My Newest Project - My Youngest Child
Last Post: Steven Harris
03-05-2019 11:56 AM
» Replies: 39
» Views: 10244
1971 moch 1
Last Post: JTS71 Mach1
03-04-2019 07:11 AM
» Replies: 16
» Views: 1329
new member
Last Post: JTS71 Mach1
03-04-2019 07:09 AM
» Replies: 3
» Views: 352
Mallory Distributors
Last Post: Steven Harris
02-28-2019 02:58 PM
» Replies: 10
» Views: 699
Last Post: Steven Harris
02-17-2019 02:25 PM
» Replies: 3
» Views: 491
UK Mach1
Last Post: Steven Harris
02-17-2019 02:16 PM
» Replies: 2
» Views: 436
1971 Boss 351
Last Post: Steven Harris
02-17-2019 02:10 PM
» Replies: 4
» Views: 701
Vin Decoder
Last Post: JTS71 Mach1
02-16-2019 08:53 AM
» Replies: 8
» Views: 6108
Bonnet latches
Last Post: JTS71 Mach1
02-13-2019 02:11 PM
» Replies: 2
» Views: 694
Vin decoder
Last Post: Oztrailer
02-11-2019 07:56 PM
» Replies: 1
» Views: 522
Ignition Timing
Last Post: JTS71 Mach1
02-10-2019 09:37 AM
» Replies: 23
» Views: 5020
New Member
Last Post: Mustangmike
02-07-2019 09:25 PM
» Replies: 8
» Views: 969