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Old 07-06-2018, 12:33 AM   #1
snowball
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Rear AC

Hi all,

My 90 burb has been awesome but int texas the heat is getting to my kids in the back seat. I've seen some burbs come with rear AC. All the lock junkyards have had the rear AC stripped. Any ideas where I can get a rear unit with all the connections?
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Old 07-11-2018, 03:22 AM   #2
Woodyboat
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Re: Rear AC

WOW, quite a few days and no one has replied. That's sort of discouraging. But, it's probably a tougher question than it first seems.

I don't have a Suburban but I do have a 92 Vandura that also has a rear unit. I don't have any idea how similar the two designs are but I would be willing to bet that they are very close given how GM has always planned for a lot of interchangeability. (Oooh now THERE is a big word! )

When you're thinking about retrofitting another unit into your 'burb, take comfort in knowing that all the lines are at least flexible. There is a rather important looking connector deal that bolts right to the back of the compressor on my rig. It splits the refrigerant path between the forward and rear units. It has a muffler type of bulb in the line that goes aft that they say can't be flushed. But the rest of the unit can be if you want to do that.

Also, the entire rear unit on my van looks as though it will come out as one assembly but I can't say for sure. I'm only saying that it looks that way. Hopefully, it would go easier than first appears.

You may seriously have some work cut out for you if you have to fabricate anything but if it were me, I'd go for it. That's because I LOVE LOVE LOVE AC and HATE HATE HATE it when it doesn't work! Your kids deserve to be comfy. My own ride is a mobility van that I use to carry my parents' wheelchairs. A couple of years ago, when the AC was on the fritz, I had my folks with me on a trip down the interstate. Mom was riding shotgun but Dad was in his wheelchair in the back and got seriously overcooked before we even realized it. The paramedics had to come and haul him out on a stretcher because he had passed out on us. This got him a couple days in the hospital and scared the absolute crap out of Mom and me. You can only imagine how we felt when we pulled into our driveway and found him unresponsive. So, I don't know about you, but I get REAL serious about keeping my van's AC running both front and rear. My folks are both 86 and I'm not losing them without a fight. I want them around for at least another ten years.

So anyway, the reason I say all of this is that being able to use parts off of a Chevy/GMC van might give you some more search options. Good luck with this. I'm really interested in how it goes. If I lived closer, I'd come over there and help you get it working.
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Old 07-11-2018, 03:44 AM   #3
Woodyboat
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Re: Rear AC

Sorry for the double post... but I got to thinking about this.

I've seen a lot of people block off their rear AC units because the extra complications make them seem intimidating. THEY'RE NOT! Rear AC units are very straight forward, stupid simple and there is no reason why they can't be made to work just fine ... adding a level of luxury that you'll soon begin to feel is NOT simply a luxury.

Like all Chevy/GM vehicles of the era, your stock system will have an accumulator that mounts to the firewall and an orifice tube somewhere very near in the intake side of the accumulator. You can find it because you will see a connection close to the accumulator that will have a couple of pinch marks in the line to keep the orifice tube from sliding too far down the line. Find the pinch marks and you can find the orifice tube.

The rear AC unit will have a Thermal Expansion Valve (TXV) instead of an orifice tube. Be sure to replace this when/if you get the entire unit out of a donor vehicle and of course, you'll also want to flush everything possible. There will be a capillary tube on the TXV that has a bulb on the end that gets fastened up against one the lines of the evaporator. This is important so that your TXV knows how to regulate the refrigerant. I always use a little hose clamp to fasten the bulb on the proper line to make sure that the connection is good. You'll see what I mean when you get into it.

Here is another little snippet of knowledge that not just anyone knows. Vehicles with front and rear AC have extra fan controls on the dash for the rear fan. So you'll need to fab a mount for the rear fan control knob. The fan motor on the rear of my Vandura is exactly the same fan motor as the front. YAY GM. But here's the important part. Whenever you run the AC, always turn the rear fan on as high as it will go. This is because the distance the refrigerant has to travel from the rear of the vehicle back to the compressor is enough that it can possibly turn from gas back to liquid. The compressor will NOT want to be pumping noncompressible liquids. Keeping the rear fan on high will help to keep it gaseous. Your compressor will thank you and I know your kids will too.
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Old 07-11-2018, 07:38 AM   #4
TKCR
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Re: Rear AC

What about using a portable unit? I looked it up on Goggle and found that there are quite a few options. I just picked a site that reviews some of the portable systems.
http://www.thecomfybuddy.com/portabl...car-and-truck/
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Old 07-11-2018, 10:09 AM   #5
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Re: Rear AC

Thanks Dave, Sorry to hear about your dad. Glad they're both doing well. I'll dig into the van option.

TK, I thought about that but I need something that doesn't depend on my reliability
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Old 07-11-2018, 10:36 AM   #6
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Talking Re: Rear AC

Quote:
Originally Posted by snowball View Post
...Sorry to hear about your dad. Glad they're both doing well...
Yup, the old man is just a little too mean to die on us. LOL Says he doesn't want to let us off that easily.
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Old 07-13-2018, 11:24 AM   #7
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Re: Rear AC

Quote:
Originally Posted by Woodyboat View Post
Sorry for the double post... but I got to thinking about this.

I've seen a lot of people block off their rear AC units because the extra complications make them seem intimidating. THEY'RE NOT! Rear AC units are very straight forward, stupid simple and there is no reason why they can't be made to work just fine ... adding a level of luxury that you'll soon begin to feel is NOT simply a luxury.

Like all Chevy/GM vehicles of the era, your stock system will have an accumulator that mounts to the firewall and an orifice tube somewhere very near in the intake side of the accumulator. You can find it because you will see a connection close to the accumulator that will have a couple of pinch marks in the line to keep the orifice tube from sliding too far down the line. Find the pinch marks and you can find the orifice tube.

The rear AC unit will have a Thermal Expansion Valve (TXV) instead of an orifice tube. Be sure to replace this when/if you get the entire unit out of a donor vehicle and of course, you'll also want to flush everything possible. There will be a capillary tube on the TXV that has a bulb on the end that gets fastened up against one the lines of the evaporator. This is important so that your TXV knows how to regulate the refrigerant. I always use a little hose clamp to fasten the bulb on the proper line to make sure that the connection is good. You'll see what I mean when you get into it.

Here is another little snippet of knowledge that not just anyone knows. Vehicles with front and rear AC have extra fan controls on the dash for the rear fan. So you'll need to fab a mount for the rear fan control knob. The fan motor on the rear of my Vandura is exactly the same fan motor as the front. YAY GM. But here's the important part. Whenever you run the AC, always turn the rear fan on as high as it will go. This is because the distance the refrigerant has to travel from the rear of the vehicle back to the compressor is enough that it can possibly turn from gas back to liquid. The compressor will NOT want to be pumping noncompressible liquids. Keeping the rear fan on high will help to keep it gaseous. Your compressor will thank you and I know your kids will too.
interesting I had noticed that my AC would blow cool from the dash, but when I turned on the rear AC on high the air would then be cold not cool.
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Old 07-13-2018, 11:35 AM   #8
snowball
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Re: Rear AC

Sounds like you're look on refrigerant.

Amazon has a refrigerant leak detector for $20. take it and walk around the ac lines until it start beeping like crazy. There's your leak.
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Old 07-15-2018, 03:04 PM   #9
White halftrack
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[QUOTE=snowball;8295087]Hi all,

My 90 burb has been awesome but int texas the heat is getting to my kids in the back seat. I've seen some burbs come with rear AC. All the lock junkyards have had the rear AC stripped. Any ideas where I can get a rear unit with all the connections?[/QUOTE
I have a 90 burb I am parting that has it. I am in Nebraska though. Donít know anything about it. Red interior. Sent pm
Posted via Mobile Device

Last edited by White halftrack; 07-15-2018 at 04:25 PM.
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Old 07-15-2018, 08:57 PM   #10
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Re: Rear AC

Here's a good read on installing a aftermarket rear ac in a suburban a 72 but same idea apply.https://www.google.com/url?sa=t&sour...a-XS3xdtZEiTxf
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Old 07-16-2018, 08:21 AM   #11
Dayton601
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Re: Rear AC

are you needing just whats in the rear, or from the firewall back
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