Question
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Followup To
Question -
I was wondering if you have any advice on how to replace the heater core in my 71 chevelle. Thanks, Joe
Answer -
Yes,I can give you step by step instructions, but I need to know if your car has factory AC. The procedure is different if it does.
Get back to me with that info, and I'll type out a list of things to do.
Dick
Yes it has factory air. Thanks!! Joe
AnswerOK, Joe, thanks.
To start with, the obvious stuff - disconnect one battery cable (it doesn't matter which one), and drain the coolant from the radiator (don't let your dog lick it - it is toxic, but sweet, and they love it!)
Next, disconnect the heater hoses at the engine side of the firewall.
For the regular "Four Seasons" factory AC,
Remove nuts from the selector duct studs that go through the firewall.
Now, from the inside of the car:
Next, remove the glove box door and the glove box. Be gentle with it, they crumble in your hands, usually.
Next, remove the center distributor duct hoses, duct cable, the center distributor duct to selector duct screws and remove the center duct.
From inside the car, drill out the lower right hand case stud using a 1/4 inch drill.
Remove the floor air distributor duct.
Unfasten and remove the selector duct from the firewall.
Disconnect the wiring, vacuum lines, and cables and remove the assembly from the vehicle.
Mark the location of the temperature door camming plate on the selector duct and remove the camming plate.
Now remove the heater core and the core housing from the duct.
If your car has the automatic temperature control "Comfortron" system, follow the below steps.
Mark and disconnect any vacuum control hoses that go through the firewall to the control head.
Remove the accessible screws and stud nuts from the heater and air selector duct from the in-car side of the firewall.
Remove 3 stud nuts from the engine side of the heater attachment, then drill out the lower right hand case stud from inside the car.
Next remove the lap cooler assembly, and the glove box door and the glove box itself. These usually crumble in your hands, so be very gentle with it!
Remove the floor outlet duct and the instrument panel pad.
Remove the air distributor duct hoses and connectors, then remove the distributor duct from the selector. Now you have to remove the programmer.
Next, remove the defroster duct screw and move the duct to get access to the selector and the heater core.
Finally, disconnect the cables and vacuum lines from the selector, and then remove the heater core and selector. Separate the heater core from the selector by removing the clamp screws.
Just a word to the wise before starting all this, give it some thought - maybe just wearing an overcoat when it's cold is easier? These cars are a nightmare to change the heater core, especially the ones with the automatic temp control system!
Sorry - don't shoot the messenger. If you want to complain, write a letter to General Motors!
Dick
