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Dynamat in, now begins AC box rebuild

M

miketyler

Member
Finished the Dynomat install on the firewall today. Now getting started on the AC box. The heater and vent doors dont come out very easy. Any tips on removing those? The box seems more delicate than the Mopar ebody AC box. Are these tough to rebuild?

EDIT: I thought the blue anodized was a nice touch though most will get covered up. I did it on the Cuda and follows the purple body color theme.
 
Re: Dynomat in, now begins AC box rebuild

The subject is pictured below. Anyone done one of these before with any tips? There are some Mopar restoration guys out of Florida that completely strip the case, bead blast the housing, then clear it. If anyone knows the trick to removing the heater and fresh air doors, olease post up those bits of wisdom. I could see no other way than splitting the retaining washer and then removing the plastic split bushing. Worked ok on the large door but the smaller door was a tighter fit in the box and eneded up doing some minor damage to the case. Nothing some resin and fiberglass cloth wont cure.

So step on in here. I'dike to here some accts of others that have done these. Maybe I will chronicle this as a DIY for others who want to take on the challenge

 
Re: Dynomat in, now begins AC box rebuild

The "washer" type retainer on the end will come off, just twist it with pliers and slide it up. No need to split it.

I did one of these about 10 years ago, used a lot of fiberglass cloth and resin to reinforce it too. I haven't cut out rivets to blast and paint the metal separate from the fiberglass, but one I have now is rusted bad enough that I need to do that. What I usually do is scrub the box with soap and water to clean the fiberglass. Then I mask off the fiberglass and blast the metal parts and then paint them a natural color. Then I spray the entire box with a clear. You can get all of those screws, washers, and retainers (like the one you need to remove in middle pic above) from AMK if you want to use correct new hardware. If you end up drilling out the rivets holding on the metal brackets and what-not, those rivets are available new but require a special rivet gun. As is typical, the rivets cost about $2 and the special gun is like $200.
 
The "washer" type retainer on the end will come off, just twist it with pliers and slide it up. No need to split it.
Click to expand...

On a 69-70 AC box it doesnt matter because the air doors arent coming out. You can get the mid door out by taking off the retaining washers and plastic split bushing and carefully spreading the sides to pop one end out and then pull the other side free. It seems crazy but looks like you would have to release the door from the shaft to get the other two out. For this reason, I left the others in and blasted them in place.

All parts are detailed now and am ready to attach seals and reassemble but am waiting on new heater core. What do you use to seal these with? I think I used strip caulk on my Cuda box.
 
Was your drain nipple attached to the box that goes through the floor? Mine broke off clean at the base and someday need to epoxy/fiberglass that bastad back into place!
 
Yes, mine is intact. I wasnt sure if I had pulled a hose or grommet off of it. All things considered, I think my box was in pretty good shape. Was considering insulating the box but its already made of fiberglass and probably no real gain in doing that.

I am planning on upgrading the underhood AC components to R134a with Sanden compressor and a true flow serpentine condensor. I did this on my Cuda and results were great. Has anyone did this on 69-70 stang and had good results?
 
There is a short piece of hose that connects to the box.

I used a Sanden compressor on mine but it's yet to be charged and ran. Using stock pulley and brackets with the adapter commonly found on ebay I think.
 
Cool - I am about half done withthe AC box and need to replace the triangular shaped rubber grommet seal that closes out around the evaporator lines. I think is supposed to be rubber but mine is hardened and cracked in two pieces. Guess I could repair it but was wondering if its repro'd? Anyone know where I can get it?
 
Classic Auto Air would be the answer to that question. I am going to reuse the firewall mat as it looks to be in pretty good shape and is a good heavy quality mat with the rubberized coating.

What about the top batting that lined the underside of the cowl thats always coming apart? What do you guys replace that with? I already have Dynomat covering the underside but was thinking some extra batting for insulative affect wouldnt hurt. Any suggestions?
 
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