I need to know how to change a heater core in a 1980 vette with air conditioning? can it be done from the engine compartment? I thought i came accross a thread where The good folks from Wilcox posted a removal diagram?

 

Well i found the Answer elsewhere, it has to come out from the interior side.

 

If you have the time and inclination to do so please post the how to for this. I would be interested since I have an 81 with air. I hope I never have to do it.

 

ok will do..

 

Pretty straight forward. Cut the in/out hoses off that connect to the core if you can't pry them off. You need to get under the car to do this.Make sure there is nothing but pipe sticking out. Remove the glove box, one duct and one consol side panel. Undo all the bolts that hold the core box in place. Don't forget the dreaded one bolt on the otherside...about 1/2 way down on the firewall. Disconnect the vac line and and the other line that comes from the heater/ac switch. Pull up,out and twist to get the box out. Only trick part maybe where the core box connects to the duct work thats behind the center cluster. You may have to remove the center cluster as well.

Open the box, replace the core. You will be able to see the blower motor still in the other part of the assemble inbedded in the firewall. Clean it out. I missed this and have something in there that makes a clicking noise on low fan.

Jim

 

Awesome thank you Jim. Here is what we got so far lol. I started removing the seats, seat belts and all the carpet today lol. Will get back to the heater core tomorrow.

 

Here's from the 79' GM Shop Manual.

 

Thank you very much Duke.

 

I think you are almost there. Loosen of the passenger side interior panel that holds the glove box door. Come to think of it I think I removed that piece entirely. The duct for the vent on the passengerside will drop down. Make sure you place it on the rear of the vent before reattaching the interior panel on install. Its a tube shape and has to fit over the male end on the backside of the vent.

I don`t remember removing the center guage cluster. There is a bit of play in the duct work behind it. You won`t see it until you removerthe interior panel that hoses the glove box door.

Jim

 

Well i am one step away from getting MR sawsall and MR hammer out the get the center consul out? Not happy, can i leave all the cables etc connected to the box or do i have to reach in and unhook them as well? I can now see this taking all winter to do.

 

There should only be a couple. Disconnect the vaccum hose. The other one looks like the old style bicycle brake cable, disconnect it.

The center guage cluster is attached to the center consol...is that what you ar talking about? There is a bolt on each side that holds it to the center consol. You need to remove the consol trim (you have one off already) on the otherside to get at the other bolt. Once you have those two bolts off and the ones that hold it to the interior panels on each side you need to pry the top out a bit. You will find it gets hung up on the light bulb at the top and wires up there. While pryed out a bit you need to loosen off the two wires (not long enough) and remove the bulb or it will not clear the dash pad. Once you get that part done you need to put the car in low gear or the bottom og the center cluster will not clear because of the radio.

Since I'm not sure if you mean the center cluster or center consol I'll post a bit more. To get the center conter consol out you need to remove the bolts on either side. There is one hidden near the shifter underneath. There are two,one on each side under the arm rest too. Once loosened off...lift and pull back. Put the car in the low gear position and remove the shift ****.

 

Ok got a little further tonight, with lots of broken sh&t to add now. Damn plastic crap. Looks like somebody didnt take their time when they put the stereo in the car. Any way.






OK how much of this has to come off? all of it or does it stay on the box.




Also where are all the mounting bolts? I found the bottom 2 how many more on the inside and on the outside?

 

See, the book makes it seem so simple but I remember going through this type of hassle with a Camaro and they are a wee bit bigger to work on. PITA then too. Thanks for the photos and steps so far.

Good luck.

 

You only need to remove the lines to the box. There should be more bolts in the top area, 2 I believe. Don't forget the one on the engine side, its not a bolt it has a nut on it.. The whole core box will come out. The heater core is inside. Once you have the box out you need to open it up. You still may need to remove the passengerside dash pad. Undo the screws on the pillar. It only clips to the top part of te dash.

Jim

 

Assuming the 1980 is similar to my 1974, this is the one on the firewall side that some people miss.



This is what you will be pulling out (vertically up and then horizontally back/out). You can see the stud that goes through the firewall.

 

Ok great, i did get the one nut on the outside as well. The heater controls scare me, as they seem so fragile.

 

Since you have the heater/ac contoller out. You may want to disconnect the lines there. But I had no problem disconnecting them at the core box.

Once you get the box out make sure you remove all the screws. It opens in a funny way...it just doesn't pull apart. maybe someone else can chim in on this. I think you almost need to twist the top a bit to poen it but can remember.

It all goes in easier by the way. Except maybe the two tubes that you need to get down through the floor. Eyeball your new core and makessure the tubes line up identically. don't bend them if they don't they break real easy. FWIW I bough my core at GM...its a delco and exact match.

 

Thank you for all the great replies.I still need to figure out how to get the duct work out, or does it come out with the heater box.

 

The only one you need to worry about is shifting the big one in the center. I found there was some play there. But I had to remove the driverside duct to the drivers side vent to get the middle one to push over enough.

You will know once you have the core box loosened off if it will come out easy. did you get the passengerside interior piece off? Thats thepiece the glove box door is in. You need to loosen it off on the passenger door pillar to get it to come forward which allows the passengerside vent duct to drop off. The whole thing will com off once you remove the screw anyway.

 

ok well i hope i understand you? I just have to loosen the dash, not remove the entire dash correct?