Factory A/C heater core removal question

[longblue72]

Ive studied almost all the threads on this in hopes that I dont screw something up..lol
But I still have a question that hasnt been answered.

Once all the routing has been removed, Is that box thats bolted to the heater core unbolted and then thats all thats dont with freeing the core box? Or is there more that i have to take out to let it come?
Thanks alot for your help guys, youve been helping me alot lately

[Andy4639]

You have to take the whole out side bolts loose and then there are some you take loose from the inside the cab. Take the hoses loose on the outside under the hood. Disconnect the heater box from the rest of the duct and boxes onside the cab. Pull it out and there is 2 metal rods that hold it in place.

[longblue72]

Andy thank you, i understand all the rest, just whats going on when you unbolt it. Im consfused about after unbolting the core box from the other box, does it just set there unbolted?

[longblue72]

Im referenceing to under the dash. the box thats bolted to the core-holding box. does that just lay there after unbolting?

[JimKshortstep4x4]

The heater core is inside the heater core box, (box to the right in the picture with the relay mounted to it). The last heater core that I changed was a matter of pulling the box out after removing the glove box and diverter box. I believe that there are four studs sticking through the firewall and through outside AC box that you will need to take the 7/16" nuts off of, (under the hood). In addition to the studs there are a couple of screws that hold the heater box in that are removed from inside the cab.

If you remove the hoses from the outside and all fasteners are out you can pull the heater box out and then remove the core.

Here is a picture of under the dash.

Jim

[1972RedNeck]

Dang, I've taken mine out three times in the last 1 1/2 years and I still can't tell someone how to remove it.

[Andy4639]

Once you have all the inside outside nuts screws apart the inside will fall off the firewall. As stated you need to have the inside undone to get the box out from under the dash and take the 4 screws that hold the core into the box out and it's done.
The deverter box and such is easy to take apart just try and not to strip the screws that hold it all together. The motor side should stay in place even after all the fastners are loosened and gone.

[longblue72]

Ive almost got it but one question, how many of the boxs have to be unbolted from the core box? Does it have to be like jims picture?
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[JimKshortstep4x4]

The "boxes" in the picture, (defrost housing, "S" connector, diverter box, and heater core housing are indexed together. It is better to remove all of them to avoid breakage of the plastic. I have never tried to pull the the heater core housing out by itself so I cannot say for sure that it can't be done!

Jim

[into69z]

I found it helpful to remove the inner fender on the passenger side as it gave me lots of room to clean and access all parts.

think of seperating the engine side box from the box inside the cab. the inside box will stay in place. There are 4 or 5 studs that go from the inside box into the engine side through the firewall. Take off all nuts and hoses on the engine side and pull the engine side box loose from the firewall. There is some weatherstriping adhesive that seals the engine side box to the firewall but it should not be too diffecuit. once you have the box seperated, the heater core is in plain site just remove the screws that hold the metal bracket.

[Andy4639]

You will not be able to do it as above state through the fire wall. The sheet metal will be in the way. You have to pull the inner box off the fire wall to gain the access to the core. Yes you may could reach it through the sheet metal but you would never get it out.
Take the inside boxes a part and that is the easiest way by far. It's only a couple of screws holding it all together.

[longblue72]

Im sure i would have messed something up without you guys, what a pain. Plenty of pine needles and junk in there aswell!
Thanks again for all of your great advice

[nuke82]

Thanks JimKshortstep4x4 for the pic, helped a lot! I tried installing a Korean heater core from Oreilly's and it didn't fit. Guess I need to swing by Classic Chevy Monday and get a better one.