Evaporator core box removal

[slofut]

With everything out of the engine bay, including suspension, and only the evap in the box, how much trouble is it to get the evaporator/heater core/fan and box off the firewall? It's an old car, and it's gotta have a heater core already. I'm sure it's a now or never situation, but I keep taking things off and diving deeper and deeper.
I guess the inside heater box and core has to come off first? I have a manual but it's at the shop and I'm at home, just thinking ahead you know.

[D_B]

Originally Posted by slofut

With everything out of the engine bay, including suspension, and only the evap in the box, how much trouble is it to get the evaporator/heater core/fan and box off the firewall? It's an old car, and it's gotta have a heater core already. I'm sure it's a now or never situation, but I keep taking things off and diving deeper and deeper.
I guess the inside heater box and core has to come off first? I have a manual but it's at the shop and I'm at home, just thinking ahead you know.

If I remember correctly, the box itself is released from the engine side. It's a split shell design so that does make it a little easier. The evap core can be had from the engine side. Once the box and evap are out of the way, you can see the core, but I think it is released from the inside by several screws going through the firewall.

Obviously you'll want the passenger knee pad and ducting out of the way.

[6880 Mike]

On factory AC cars, you have to work from both sides. If memory serves, the interior box has to come out before you can remove the evaporator case from the underhood side.

[71scgc]

You have to work from both sides. Remove the RH lower dash pad and AC duct on that side. Remove any bolts you can see from the inside, tag and bag them. Go to the engine side and remove all the bolts you can see there. There are bolts around the fan motor which are somewhat hard to get at. On a 70-72 no prob if you remove the egg crate. Others you will have to feel for. Again, tag and bag. Once all are out, remove the box/core/fan as a unit. If you order a new cover from AC Delete (acdelete.com) you can use your existing heater core which will stay on the firewall after removing the AC box. If you go with a OE style non-AC cover, you'll need a non-AC heater core. The AC Delete cover is pricey, but saves you from having to change the core out. They also require a little fabbing/altering in order to mount the blower resistor and clearing the heater core inlet/outlet. They come with some fairly good instructions, but aren't year specific. Also a little glossy, but some scuffing and semi-gloss black fixes that. Pay attention to the orientation of the fan when remounting and reuse the support on the inside of he fan. Once mounted in the firewall, seal the perimeter with some Ultra black RTV. You may have to get inventive with the blower resistor mounting. This has a lot to do with how much wiring length you have in your car.
This is an easy upgrade. Be meticulous in your work and you'll have no big problems.
I de-aired my 71 almost completely this past summer during a frame changeout. Both inside and out.
Carter