Calling all A/C Gurus - Need System Upgrade Help
Thread Starter
Drifting
Joined: Aug 2005
Posts: 1,289
Likes: 3
From: East Waterboro Maine
Calling all A/C Gurus - Need System Upgrade Help
Currently my A/C system is in pieces (lots of them) and it's time that I start thinking about how everything will need to go back together (I know, I know - just in time for winter 
).
When I bought the car the A/C system was inoperable because the compressor and condensor were missing. The rest of the system seems to be intact. So here are my questions:
1. Since I'm at it, I'm guessing I should switch over to R134a, right?
2. If I do upgrade to R134a will I need to switch out? What modifications to the original R12 system will be required?
3. Are there any components that are subject to wear that I should inspect and/or consider replacing while I'm at it?
4. Any other tips or tricks I should know?
Thanks in advance!
). When I bought the car the A/C system was inoperable because the compressor and condensor were missing. The rest of the system seems to be intact. So here are my questions:
1. Since I'm at it, I'm guessing I should switch over to R134a, right?
2. If I do upgrade to R134a will I need to switch out? What modifications to the original R12 system will be required?
3. Are there any components that are subject to wear that I should inspect and/or consider replacing while I'm at it?
4. Any other tips or tricks I should know?
Thanks in advance!
Burning Brakes
Joined: May 2004
Posts: 1,100
Likes: 3
From: belle plaine ks
You may find it cheaper to remove what you have and put in aftermarket like vintage air and or hot rod air or classic auto air. Start pricing the parts to do it and see if you stay under the price to put in an aftermarket. Unless you are bloomington gold bound don't be faithful to original. There are pluses to putting in aftermarket such as not having the ac unit setting next to a hot engine, as the aftermarkets all reside in the cab. The downside to aftermarket is installation. It's not really that difficult, but you are going to have to remove part of the dash to get at everything plus do some engine bay work to remove old parts.
Thread Starter
Drifting
Joined: Aug 2005
Posts: 1,289
Likes: 3
From: East Waterboro Maine
It's going in a 1971 BB coupe with manual transmission.
Replace everything? I just assumed that, since (I think) I only need a few parts it would be cheaper to buy what I need than to replace everything. Looking at Napa I can get a new compressor for about $180, and from other parts houses I can get a new drier/reciever for about $20, a POA valve for about $100 and a new condensor for $240. Are there other parts I would need? I'm thinking I may be able to find a used condensor for a cheaper price, but would likely buy the other stuff new or remanufactured.
Guess I'll reserach some aftermarket stuff to see what's out there.
My car is completely gutted at this point so access is a non-issue.
Replace everything? I just assumed that, since (I think) I only need a few parts it would be cheaper to buy what I need than to replace everything. Looking at Napa I can get a new compressor for about $180, and from other parts houses I can get a new drier/reciever for about $20, a POA valve for about $100 and a new condensor for $240. Are there other parts I would need? I'm thinking I may be able to find a used condensor for a cheaper price, but would likely buy the other stuff new or remanufactured.
Guess I'll reserach some aftermarket stuff to see what's out there.
My car is completely gutted at this point so access is a non-issue.
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
Get a parallel flow condenser for less than $150, then you're covered for all refrigerants. Much more efficient.
Dumping the poa system and going with an oriface tube evaporator isn't a bad idea.
Dumping the poa system and going with an oriface tube evaporator isn't a bad idea.
Thread Starter
Drifting
Joined: Aug 2005
Posts: 1,289
Likes: 3
From: East Waterboro Maine
So if I get this special evaporator I don't need a POA valve?
Who sells Parallel flow condensors and Oriface Tube Evaporators?
Are there different types of compressors I need to consider?
Le Mans Master
Joined: Sep 2004
Posts: 5,116
Likes: 5
From: Livonia MI
Sound's like you're on the right track just going back to an original system using R-12, as not that expensive for a few pound's. Find out what kind of oil charge in the replacement compressor, if older mineral go R-12. A new reciever/drier's a good idea, but POA's optional, unless it's missing. Best fill a bit of refrigerant or nitrogen gas and at least spray the joint's with soapy water after it's back together. Connecting a vacuum pump to suck out any possible moisture, is pretty much industry standard. Biggest problem, the original factory A6 compressor seal's tend to be real leaker's, even the rebuilt one's. Another thing to consider about R-134a, is on it's way out too.
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Racer
Joined: Mar 2010
Posts: 378
Likes: 0
From: NW sub of chicago IL
I am in a similar situation but I have all my parts. It's cheaper to use what's there but there's also no grantee that it will work or if it is leak free. I would recommend pressure testing the parts and test the expansion valve. The process for testing your parts should be in the gm service and repair manual for your year.
Me I am sending my original parts to classic auto air to see if they even work. I am also keeping r12 because it work better. The reason for switching to r13a was that it was cheaper, way cheaper now r12 it doesn't cost anywhere near as much.
Me I am sending my original parts to classic auto air to see if they even work. I am also keeping r12 because it work better. The reason for switching to r13a was that it was cheaper, way cheaper now r12 it doesn't cost anywhere near as much.
Racer
Joined: Nov 2008
Posts: 491
Likes: 0
From: Myrtle Beach South Carolina
Consider putting in 1979 (version) a/c. It gets rid of the POA stuff. I did that on my 73 with the newer style compressor and a '79 Evaporator (fits right in the a/c plenum). I found a place in California that makes condensers. Ebay had it for $129.
Racer
Joined: Nov 2008
Posts: 491
Likes: 0
From: Myrtle Beach South Carolina
Most all condensers are parallel (eBay has 'em)
The '79 evaporator comes with the orifice control device (it's just a fancy piece of plastic inside the incoming tube)
Get the newer Sanden compressor - it takes about 4HP, the old GM compressor takes about 18HP.
If you don't care about originality, take a look at:
http://www.classicautoair.com/68_76_..._Chevy_AC.html
