Topic: 71 Heater Core Replacement, not coming out...
in Forum: C3 Cooling and Heating Systems
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Replacing my heater core since i tore out the console, then side panel, then... you know how it is.
I took out the three screws that hold the heater/AC assembly to the firewall- One up top, 2 below- still can't get it out.
Can anyone tell me what i missing?
I have diagrams- everything is right. It should be one top, 2 bottom.
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There seems to be this simple flat thing-not a bolt- holding this thing up. Not in the assembly manual, it is the round thing directly in the middle that goes into the firewall.
I would have thought this was just a fastener for the heater assembly, not bolted through the firewall. I checked. I have one accesible nut that can be taken off in the engine bay- I did it, it was not it.
OK, hope this helps. Behind the top stud ( I believe its the one in the pic) that holds the evaporator case to the firewall there will be a second nut. What I did is carefully pry the case back so I could get an end wrench on it. Then discard when it goes back together. I'm not sure its whats holding you up, but it did me until I found it. "T"
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There will be more than 1 stud going thru the firewall holding the heater/AC plenum in. There are a couple on the bottom, if memory serves. The studs going thru the firewall also hold the AC plenum on the engine side of the firewall. You may have to dig around with a screwdriver or some sort of scraper to uncover them...they may have been covered with a type of undercoating/sealant from the factory.
The stud in your pic is at the top of the A/C plenum under the hood, and it will be the easiest one to locate and get the nut off of. As Terry points out, taking the one nut off from the A/C plenum under the hood may still leave you with one holding the heater plenum to the firewall under that.
It's been years since I've been that far into one of these systems, so my memory ain't that good. Patience is a virtue here...
The stud in your pic is at the top of the A/C plenum under the hood, and it will be the easiest one to locate and get the nut off of. As Terry points out, taking the one nut off from the A/C plenum under the hood may still leave you with one holding the heater plenum to the firewall under that.
It's been years since I've been that far into one of these systems, so my memory ain't that good. Patience is a virtue here...
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There are several online "sources" dealing with C3 Heater cores- every one is not complete.
I'm going to try and change that so there's less headaches involved.
Namely, its heater cores with AC cars.
I have many pictures, that'll help. Just finished rebuilding the heater control box- still not back in, but at least the hard part is done.
Actually, the hard part ios taking it out.
That one top left is a stud that passes through the firewall AND is THROUGH the AC cover, Unscrew that nut, located just below the small headlight vacuum mechanism (I believe). Hardly noticeable, but it's there.
You'll also need to lightly push it through, back into the cabin. It'll be sort of "bound up."
Every article or directions leave out certain things, obvious, but nonetheless, vital.
Vacuum hoses have to taken off before the box can be pulled from car, along with 2 RT side sensors and a light bulb bracket. Each vacuum line ios color coded, but I took the above shots to make sure they go back where they were pulled from.
Unbolt the cable on top (then put the bolt back in to not lose it) and gently pry off the round "pie" clip with a screw
driver under it. After it's off, pull the cable end "o"ring out, then snap back on that small piece or you'' lose it.
driver under it. After it's off, pull the cable end "o"ring out, then snap back on that small piece or you'' lose it.That top left stud causes almost all the problems. I ended up with two holes there. I actually had a small crack between the two holes- not a big deal, but don't start pulling and tugging, otherwise it could crack. I'm unsure if I did the damage or not, but I don't think so- the other hole was added i think from a prior heater core replacement, about 20 years ago.
Move the stereo/speaker wires out of the way.
Also, the seal kit from Zip says it includes everything. It doesn't, at least for nmy 71. Later models, displayed in the directions, make do with different seals.
Not a big deal, but sorting out which goes where would have made the kit a heckuva lot user-friendly (and in my opinion, the only real customer service way to go).
I mistook several seals for heater core rebuild, but they were AC evaporative seals (my AC box/unit in the engine bay) is A-ok (not needed). Yes, you'll get a bunch of "extras" - extra headaches.
On the side, trace the "Y" shaped bracket. The top screw is different (it holds and screws into the inside metal part that extends down from the top (where the heater core is).
After removing it (along with the bottom 2), set aside Y bracket and rescrew them back in (to not lose 'em).
On top, unscrew the 4 top small screws on the metal perimeter. The whole HC assembly It should pull out. The brass coolant hoses from the heater core are secured by:
A formed metal plate. 1 small screw up top and bottom. And a the bracket that crimps down on the brass tubes. Every HC is slightly different, so there are variances. It wonj't re-install as perect as the old one is now (that's OK).
After those are out, unbolt that stud nut- why it's there I haven't a clue. It can't even be tightened all the way down- the metal is pre-formed bead that sticks up and the nut hits it, not allowing it to spin after a certain depth. I tightened it down as far as it would go.
Turn over the HC. There are 2 straps that hold it to the case, each with 2 small bolts. Take 'em off and the heater core can be twisted a wiggled out.
in Forum: C3 Cooling and Heating Systems
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