Heater Core Replacement 73 454 with AC

I wrote these detailed instructions while taking the heater core out of my ‘73 454 / AC. Hope it helps those facing this task. Remember, time and patience...

.50)	Remove passenger door sill plate.

.75)	Pull carpet back from firewall, carefully pulling from under right right side vent (in front of door)

1)	Remove the emergency brake console.

a) 2 screws on each side.

b)	3/8" bolt, accessible through passenger side storage compartment. Small hands are a big help (I’m 5'9"). This bolt attaches to the bracket underneath the brake console and must be removed.

c) Pull the emergency brake up as far as it will go.

d) No need to remove console (see step 3 h)

2)	Remove the 2 kick panels that attach to the front of the center console. These are below the radio, on each side of the trans. hump. Should be 1 screw each side.

3)	Center (shift) Console

a)	Remove 4 top screws on each corner of shift plate.

b)	Unscrew, normal counter clockwise, chrome shifter button (auto trans). Might be tight. You’ll see the spring when the button is off.

c)	Unscrew, normal counter clockwise, shift knob.

d)	Shift transmission into Low

e)	Carefully lift front end of console plate. The back end has tabs and will break if forced. While the fron end is tilted, disconnect the bulbs and leads.

f)	Remove console plate.

g)	Remove 2 screws from front side of console (forward most trim plates). 1 on each side.

h)	*** This is one of the hardest steps *** There are 2 3/8" nuts underneath the top side of the console, at the front. The post that these nuts attach to are actually part of the center gage / radio bracket. Smaller hands than mine would be a plus. I lost a few layers of skin on this one.

i)	Slide the emergency brake console back slightly so you can lift the back end of the center console over the front end of the brake console. Did that make sense to you?

j)	If you’re careful, you can wiggle one end of the heater/AC control assembly underneath the lip of the center console. Then with continued patience, wiggle the console around until you get the other side of the heater/AC control assembly under the lip. If this causes too much grief, removing the 2 tiny screws on the heater/AC control assembly may give you some more free play.

k)	Remove, at last, the center console.

4)	Instrument cluster bezel
 * The bezel is supposed to be one piece. However, many are broken at the bottom edge of the center vent at the thinnest point. I tried to expoxy, but it didn’t hold. Good news is that it’s covered by the vent piece anyway. ***

a)	Remove 2 screws on each side

b)	Pull off windshield wiper knob

c)	Remove 2 side screws & 1 screw at top of center vent. If your bezel is in 2 pieces, it should want to lean forward on its own. If so, remove bulb and wiper connection and proceed.

d) Remove radio knobs & 2 5/8" nuts

e)	Carefully pull bezel forward over radio knob stems. *** extra care to support the upper vent section if your bezel is still in 1 piece.***

f)	Remove all bulbs and connections from center vent and instrument cluster. Labeling the leads will make reassemble a lot easier. Leave the gage cluster attached to the bezel.

5)	Radio

a) Disconnect antenna.

b)	Remove bracket nut from right side

c) Disconnect speaker and power leads.

6)	Map pocket

a) Open passenger door and remove 3 screws

b)	Remove 2 screws on the top end

c)	Pull out pocket from the top. It’s a little snug, that’s normal.

d)	Disconnect bulb and wires from clip.

7)	Remove vent piece that went into the map pocket vent

8)	Center Vent

a)	Undo bulb on right side of center vent

b)	Carefully twist and rotate the driver side of vent to remove. Patience.

9)	Defroster vent

a)	Remove 2 bolts. The drivers side bolt also has a clip that holds the radio antenna cable. The cable runs behind the vent.

10)	Remove 3 bolts that hold the heater distribution box together. Pull apart just enough for clearance. No need to remove left section.

11)	Jack up the front end of your car. Be safe, you’ll be working underneath, so use ramps, jack stands, etc.

12)	Drain radiator

13)	Follow the 2 heater hoses to the firewall. There is a thin metal plate attached to the firewall protecting the hoses as they go up and attach to the heater core. Remove the 3 bolts from the plate.

14)	Remove heater hoses from core

a)	You will now have a reasonable clear shot at the hose connections. Loosen both clamps. If you’re planning to replace (recommended) the older hoses, slitting the hoses would make removal easier. Otherwise carefully remove the hoses.

15)	Heater distribution box / core assembly

a)	From the top of the engine compartment, remove 1 nut. On my car, this also has a clip for wires. It’s near the top of the firewall, closest to the passenger fender.

b)	Back inside, remove 2 bolts and 1 screw from heater box. Why 2 bolts and a screw, who knows. Maybe they were all supposed to be bolts.

c)	remove heater cable screw

d)	Tilt heater box assembly slightly forward and remove 2 vacuum hoses. The front (red) hose is a little hard. There is a small clip, small thin needle nose pliers works well. The back (brown) easier pulls off back of actuator.

e)	You should now be ready to remove the assembly. The core inlet and outlet tubes feed through and then down the firewall. So, carefully tilt forward while lifting. It will rotate, top end first, and then out.

16)	Core Removal from Heater Distribution Box - Part 1

a)	Remove 4 screws on top plate. The shorter screw is by the plate post.

b)	Remove 2 screws on bracket covering the inlet and outlet core tubes.

c)	Remove screw (longest in this group) to bracket that secures the core tubes.

17)	Core Removal from Heater Distribution Box - Part 2

a)	Remove the 3 screws attaching the cable bracket from top of heater box.

b)	You should now be able slide the front of the heater box out. The core is attached to the back of the steel gray panel you’re removing.

c)	Remove 2 screws each from both core hold down brackets.

19)	Ta da. Removal complete. Now wasn’t that fun!

20)	Clean heater box as desired. My was dirty. Imagine that, after only 33 years

21)	Installation

a)	I’d suggest a seal kit for the heater core and assembly box.

b)	As a precaution, carefully connect the heater core to the hoses. Do this in the engine compartment. Then you can fill the system with water and do a pressure test. If that doesn’t work for you, take it to a radiator shop and have it tested. You certainly don’t want to re-assemble everything and find out you have a bad replacement core.

c)	After testing, drain system and remove heater core.

d)	Install in reverse of 1 through 17.

I don’t think I missed any steps, screws, or bolts. I’ll confirm during the installation process. Photos to follow (one of these days). Good luck. Hope this helps. Randy