Suburban A/C fix + Vintage Air?

[swissarmychainsaw]

Hey all. I have a 1976 GMC Suburban, with a 6.0 LS2 (carb'd) out of a trailblazer ss. (bought it this way).

My cab has factory (front-only) A/C and it seems that all the stock parts are there except for the compressor and lines.

How feasible is this:
Uses all the stock components for the front A/C.
Add the LS appropriate compressor/bracket.
Use Factory switches (so the temp control etc. is stock)

Somehow Tee off this and add a Vintage Air for the rear, and make that switched so you could run them independently.

I have read that some guys have done this with a mini/slimline.

Is fairly doable? I honestly know NOTHING about A/C and have been reading up on it.
It seems like a fairly straight forward project (hahaha).

Nick

[68Timber]

The slim line unit, you would still mount this overhead in the rear? I've read that the new aftermarket ac packages blow much colder and are a big improvement over original OEM units. But for purposes of retrofitting AC into the back of a Suburban, if aesthetics matter, it's going to be hard to beat using the original OEM pieces. Probably a lot cheaper too, if you buy a parts truck that has what you need. I'm not against aftermarket AC at all, just thinking out loud here.

[swissarmychainsaw]

I'm definitely open to using original stuff.
It's a matter of finding a donor, then getting it all to work, and I'm no A/C guru.
I agree the stock units look much better, but right not ordering new stuff and installing it is enough of a project! :-)

[68Timber]

I'm no AC expert either but I did replace the compressor and drier on our old Yukon a few years ago after watching a few youtube videos. Think of it all as a hydraulic system that produces lower temps instead of line pressure for a ram. It's all plug and play and the only real problem is the potential for leaks. Use the force and you'll be fine. I'm not trying to oversimplify, but really there's no magic going on here. Once it's all bolted on and buttoned up, you need someone to pull a vacuum on the system and charge it for you, but you'll need to do that either way. Also need to read up on converting freon to R134a and use the parts needed to convert. You might need custom lines made to hook up the factory system to the newer LS compressor, but I think I read somewhere here that there's an existing set of OEM lines that fit. I have since fixed the rear AC on the Yukon since the compressor was replaced. Once you burst the mystique bubble, it's just car parts. If I can do it, any shade-tree can.

[swissarmychainsaw]

You are welcome to come visit and lend a hand! I'll buy the beer!

I just found a donor (3 actually - this guy has more Suburbans than I do!).
He's asking $250 for "everything" for the rear A/C.

I figure I'll give that a shot. Going to get it this week.

[68Timber]

No kidding, you can do it. Donor truck really makes it simple, when you have to take it off, you're well versed in how it goes on.

[swissarmychainsaw]

I went and picked up the Rear AC from a Donor burb today. I think it was an 86, I picked it because it had grey interior pieces.

All went smoothly.

Note the long AC lines that run under the car



The first unit I looked at (and removed) was cracked, this one was in good shape:



Cover and side trim is in good shape ( I have some paint for it anyway )
Note the headliner cardboard, I grabbed this since its cut for the AC.
I also grabbed the blue headliner (mine is currently Grey)



Harrison:








There was a large gauge Purple wire connected to this ( condenser).
Can anyone confirm, but I think this is the "low/off/high" for the fan, right?




This is the combo switch for the rear window (top)
And Rear AC, hard to read but it says Lo OFF High



I have no idea what these wires go to, any wiring diagrams around?



Thoughts and questions:

1.) There is oil coming out of the lines... is that old refrigerant? I have read this should be cleaned out.
How should I clean it out? I have an air compressor, not sure what if anything I should spray in the lines.

2.) When I dropped the headliner I noticed that these things have NO insulation in the roof. No wonder it gets hot.
Anyone use that peel and stick sound/temp insulation stuff? I'm looking for a recommendation.
Seems like a no-brainer to insulate while I have the headliner down.

3.) I have read that these lines have o-rings that should be replaced and lubricated. Anyone have a source and some input on what to lubricate the o-rings with?

4.) when installing the rear cover, what else should I wire up there? Lights? Speakers? Disco ball?

Thanks for the help!

[68Timber]

Those parts look great! Can you get the wiring you don't have?

I used an AC system flush product that I bought at autozone, spray it in and blow it out with compressed air. For the o-rings, I'd bought a 4 oz bottle of AC system oil that's added to the system when you charge it. I used it to lube the new o-rings before I installed them. Peel and seal would help a bunch with noise, but I don't know how much it'd help with insulation. I'd use it anyway, while you're there.

[swissarmychainsaw]

Did you just use some generic 0-rings?

I bought a box of multiple sized 0-rings and have used them with success on power steering lines. Not sure if they will work for AC.

[68Timber]

I used ac specific o-rings. I was replacing bad parts that came with new o-rings.

[swissarmychainsaw]

So are we going with R-12 or R-134a?

I'm putting together a shopping list, as an update I have:
2008 6.0 LS2 Trailblazer SS engine (no AC currently) Carburated.
1976 Body, with Front AC only
Adding Rear AC Donor was an 1986 Suburban

Shopping List
1. AC O-ring kit
2. Oil for o-rings (PAG for R134?)
3. Compressor (from the Trailblazer)
4. A/C Receiver Drier / Accumulator Should come with new compressor
5. High mount bracket for compressor
6. A/C Refrigerant Hose ( for rear AC )
7. Condenser (Radiator 1986)

Going to add some kind of insulation on the roof under the headliner.
Not sure what to use yet. Might just go with cheap Aluminum bubble wrap from Home depot gluing it on with 3M spray 90 adhesive (using this for the headliner also).

I guess I need a way to connect the 1976 Controls to the new 2008 Compressor.
No idea how to do that yet.

[swissarmychainsaw]

Today I removed the rear headliner (which is sagging badly)
Also, it had some water stains on it. Maan, it's tempting to give in to "shipwrights disease" and start fixing everything
I find.

I was shocked to see that the roof rack is only tied into the outer roof skin and not the cross members!
I have a plan to add a beefy roof rack, using the existing mounting holes.






I needed to drill some holes, but got the AC unit hung (test fit)



Need to cut a hole here for the hoses




I assume both of these should have O-rings right?



This one fell out



I think it goes here

[swissarmychainsaw]

I hate to cut sheetmetal, but here we go:



Test fitting the manifold:



Manifold Cover - Note the original screws go nowhere on this, I'll have to fab up a bracket for this and the overhead cover:



Oh, and here is a shot of the underside of the Original Headliner on my Burb.
Definitely had some water in there. My son said it "looks like Art!"

[Hubscrub]

I'm following this I'm gonna work on my 91 burbs air soon. Nice work so far.

[swissarmychainsaw]

Work on the AC headliner (which is different than the non/AC one):

Used three methods to scrape the old foam backing off the cardboard.






Then I used 3M 90 Spray Adhesive from Home depot



The bubbles were disappointing as hell, but it looked a little better in the morning.
This was the old headliner (all the foam backing had deteriorated), and I had read that using the old stuff does not work well, as the foam helps make the final cloth look very uniform.

So if you try this at home, us NEW headliner material. I'm going to see if I can buff it out a bit and use it as is for now...

But man I was sad last night!

[swissarmychainsaw]

Is this thing on?

I have watched some videos on this and it seems *really* straight forward to charge the system.

Things I need to sort out:
How to turn on the compressor, do I have the stock plug on my truck to do this?
Rig up a switch for the rear fan

I bought an O-ring kit and oil, and some system flush to clean out my junkyard parts and get them together.

In other news, I dropped coin on the Holley adapter and Sanden pump kit.

I know there might be a cheaper way to do this, but my time is somewhat limited and a "plug and play" kit, where everything lines up correctly is just the ticket:

[swissarmychainsaw]

Anyone have a picture of their suburban's ac lines and hoses, the under hood view?

I need a pic of what it's supposed to look like when I'm done!

Thanks!

[SCOTI]

Did your used-parts source not have anything you could look at?

[swissarmychainsaw]

Originally Posted by SCOTI

Did your used-parts source not have anything you could look at?

My parts guy is just a dude about 1.5 hours away that is parting some 80s squares. Most of his stuff was not very complete, and when I was there we did not have much time so I was focused on getting the rear a/c and lines from under the truck. The whole front clip, motor and lines were gone from that one.

I have a manual I can look at, not a big deal.

I also found this, which inspired me to (spend more money...cough) err do it myself:
https://youtu.be/Pdq8JAlct6s

[Irish1941]

A little late to the party but it aint that hard. LS carb'd is odd but in your favor with no ECM input for the ac & fuel system. Shame all that EFI engineering is gone.
Anyway this diagram may help you out with your lines.

[swissarmychainsaw]

Originally Posted by Irish1941

A little late to the party but it aint that hard. LS carb'd is odd but in your favor with no ECM input for the ac & fuel system. Shame all that EFI engineering is gone.
Anyway this diagram may help you out with your lines.

Thanks a ton! Can you post the part where it shows the labels?
The wiring is the part I really need!

I would prefer to have the stock FI for sure, but I sort of get why some folks use Carbs: it's relatively simple, especially if you "get" carbs.
My Holley is not yet running to its full potential, but I'm getting there.

Thanks again for the diagram!

[swissarmychainsaw]

Here is the original Accumulator on my '76 Burb 3" diameter.
It's different than the '86 (which had rear ac).
Notice this has only one connection to it and one service port (unless it's on the bottom???):



Here is the Receiver/Accumulator for the '86:



Question is: which one should I use?

[swissarmychainsaw]

In other news:

Parts from Summit came in:



Found Duct Insulation at the Hardware store and thought I'd try it.

[hatzie]

The wiring diagrams are in the manuals thread. You'll find the rear AC wiring separated from the main harness diagram.

[Hubscrub]

That insulation looks like a good idea.