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If I can add to Barry's question, what does the conversion typically cost?
:confused
:confused
Question on AC
- Thread starter BarryK
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IH2LOSE
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Barry first and foremost I am no expert! I am still learning,
R12 was absolutely the best refrigerant for a car, There can never be an equal replacement unless they discover a new way to cool a car off ,
That being said R134A is the replacement gas we have available
I have converted several cars over the years (even when R12 was still available) My Caddy is an excellent excample,Large cabin and withe the top up and windows closed it gets so cold you have to turn off the air in the car,
R12 was absolutely the best refrigerant for a car, There can never be an equal replacement unless they discover a new way to cool a car off ,
That being said R134A is the replacement gas we have available
I have converted several cars over the years (even when R12 was still available) My Caddy is an excellent excample,Large cabin and withe the top up and windows closed it gets so cold you have to turn off the air in the car,
Stan's Customs
Well-known member
I too have done several conversions....many in fact. In the area I live (central Texas) I have never been pleased with the 134A conversions in really warm weather. Beats nothing...but R12 really works when it's 110 degrees while other refrigerants don't. Most cars that use 134A have a larger condenser than those originally equiped for R12.....Unless you change to a larger condenser you loose cooling capabilities when you go to the less efficient 134A refrigerant. (Freeze 12 is mostly 134A)
Don't get me wrong...134A cools, especially in milder climates ....just not near as well....
It's well worth the expense to buy R12 ..cost $100 or less. More than that and the shop is pulling your leg...R12 is plentiful at $25 a can...and like was mentioned, can be found on E-By and very likely other places locally. A parts warehouse that services garages would be a good bet too...not Pep Boys etc...
Any good garage can service your A/C...it doesn't have to be an a/c specialist facility. Find an independent old school established mechanic...he'll fix you up.
Don't get me wrong...134A cools, especially in milder climates ....just not near as well....
It's well worth the expense to buy R12 ..cost $100 or less. More than that and the shop is pulling your leg...R12 is plentiful at $25 a can...and like was mentioned, can be found on E-By and very likely other places locally. A parts warehouse that services garages would be a good bet too...not Pep Boys etc...
Any good garage can service your A/C...it doesn't have to be an a/c specialist facility. Find an independent old school established mechanic...he'll fix you up.
- Thread starter
- #24
Larry and Stan
thanks for the comments on both sides........ I have some thinking to do on this I guess. I know the cabin in the Vettes is small but those hot August days that are 95*-100* w/ 95% humidity can really beat you down not to mention the added heat coming thru from the engine bay.
well, i have a few weeks to figure this out. I don't really need to make a decision until after the car gets back from the paint shop I guess, no real need to rush into it and have to get it done before painting
thanks for the comments on both sides........ I have some thinking to do on this I guess. I know the cabin in the Vettes is small but those hot August days that are 95*-100* w/ 95% humidity can really beat you down not to mention the added heat coming thru from the engine bay.
well, i have a few weeks to figure this out. I don't really need to make a decision until after the car gets back from the paint shop I guess, no real need to rush into it and have to get it done before painting
gmjunkie
Well-known member
Barry, I do 30 to 40 R134a conversions a year!! As I said before about the Brass Monkeys,A man that knows A/C systems can make it Cool every bit as Good as any R12 System!! Problem is most guys buys a Cheepo kit at Auto Zone,Advance or Discount Auto Parts!!! That has a Half azz Instruction book and dose not go in to the Mechanics of How,What,When, or Where on a A/C System!!! To retro a system right,Now Right is the Key word here!! You must!!
Remove all lines and fittings,Orifice tube,expansion Valve or POA valve Depending how system is equip!! Flush entire system,Evaporator,all hose's,and Condenser and dump oil out of compressor!! Replace receiver drier, Orifice tube (if so equip, Ford Blue has a bigger orifice, or a smart tube R134 expands differently) and all o-rings with the green 134a O-rings add 4 oz ester a/c oil in new Drier add 4oz oil to condenser and 2-3 oz to compressor!! Close system back up and draw a DEEP vacuum!! I like to pump it down for at least a hour sometimes 1 1/2 hr depending on size of system!!! R134 uses 10% less and this Has to be weighed in 1 oz to much or 1oz not enough the system WILL NOT WORK properly!!! Most guy's screw up Right Here!! They don't have all air bled out of the lines on there gages!!! Which is about 5 oz of refrigerant!! And they get them under charged or over charged screw'n with it!! I always make sure that my gages are bled and full of Liquid Refrigerant and then I set the 30# tank on my Digital scale and weigh in the exact amount of R134a which is 10% less than what R12 calls for!! I rarely use R12 anymore unless it is a Working R12 system and only needs a lb or so!! I use Freez12 on a system that is very low from setting around and not being used!! It is not uncommon R12 unit to lose 1/2-1 lb year if it is not being used!!
This whole R12 thing is Just Political BS anyway,and I refuse to make some ******* Rich!!!!
Ozone Smozone!! Freon don't go up it go's down!! That's why your supposed to Leak check under Evaporator,Condenser and fittings and not above!! So the Big Wig's say after freon is in the atmosphere the chlorine molecules brake off and go to the Ozone!! But one swimming pool on a 90 deg. day will put more Chlorine in the atmosphere in a week than 500 leaking car a/c units do in a Year!!
So I say , Take away all the Politicians Swimming Pools and Let's be Cool!!
And Yes I'm a Certified Air Conditioning Technician!!(ASE,GM,Ford,Nissan,Four Seasons,Carrier)
PS I forgot I get $300-$400 for this depending on what the Receiver drier cost and if the system needs other components
Remove all lines and fittings,Orifice tube,expansion Valve or POA valve Depending how system is equip!! Flush entire system,Evaporator,all hose's,and Condenser and dump oil out of compressor!! Replace receiver drier, Orifice tube (if so equip, Ford Blue has a bigger orifice, or a smart tube R134 expands differently) and all o-rings with the green 134a O-rings add 4 oz ester a/c oil in new Drier add 4oz oil to condenser and 2-3 oz to compressor!! Close system back up and draw a DEEP vacuum!! I like to pump it down for at least a hour sometimes 1 1/2 hr depending on size of system!!! R134 uses 10% less and this Has to be weighed in 1 oz to much or 1oz not enough the system WILL NOT WORK properly!!! Most guy's screw up Right Here!! They don't have all air bled out of the lines on there gages!!! Which is about 5 oz of refrigerant!! And they get them under charged or over charged screw'n with it!! I always make sure that my gages are bled and full of Liquid Refrigerant and then I set the 30# tank on my Digital scale and weigh in the exact amount of R134a which is 10% less than what R12 calls for!! I rarely use R12 anymore unless it is a Working R12 system and only needs a lb or so!! I use Freez12 on a system that is very low from setting around and not being used!! It is not uncommon R12 unit to lose 1/2-1 lb year if it is not being used!!
This whole R12 thing is Just Political BS anyway,and I refuse to make some ******* Rich!!!!
Ozone Smozone!! Freon don't go up it go's down!! That's why your supposed to Leak check under Evaporator,Condenser and fittings and not above!! So the Big Wig's say after freon is in the atmosphere the chlorine molecules brake off and go to the Ozone!! But one swimming pool on a 90 deg. day will put more Chlorine in the atmosphere in a week than 500 leaking car a/c units do in a Year!!
So I say , Take away all the Politicians Swimming Pools and Let's be Cool!!
And Yes I'm a Certified Air Conditioning Technician!!(ASE,GM,Ford,Nissan,Four Seasons,Carrier)
PS I forgot I get $300-$400 for this depending on what the Receiver drier cost and if the system needs other components
- Thread starter
- #26
wow Junk, you want to come out and do mine 
not sure which way I'm going to go yet, but if I go the conversion route I think I'll use the info that last post as a check list for the shop
not sure which way I'm going to go yet, but if I go the conversion route I think I'll use the info that last post as a check list for the shop
Stan's Customs
Well-known member
Sorry GM...Not trying to flame you or get flamed....
I too have been certified since they started doing certifications in the 70's, and still am. I didn't say you couldn't make 134A cool..I said not as good as R12. I stand by that. I very rarely have come backs and my customers are satisfied with the cooling....As for my personal stuff , vintage iron particularly...I perfer R12, because I can tell the difference....usually 4 or 5 degrees at the duct.
The amount of 134 A "is" critical, as you said, and often guess work when you are just topping off a system, among other times. Many old systems do not have the tags stating how much refrigerant was recommended from the manufacturer...therefore difficult to determine what is 10% less, if that is the method you use.
Dual R12 systems like old Surburbans that use both an expansion valve and an orfice tube...are particularly awkward to just top off.....once retrofitted.
The orfice tube and expansion valve fluctuate out of sinc and the head pressures are hard to nail down.....making it even more difficult to get the proper amount of refrigerant unless you start from scratch with a precise measured charge.
Now back to old cars which is really the topic ..the older they are the more this applies....again in my view.
Even if the 134A would cool as well. (Can we agree to disagree there, without animosity...I'm just stating my opinion) and I "do" agree with your retrofit procedure for the most part... the cost of doing a proper retrofit exceeds the cost of R12 refrigerant, especially if refrigerant is all that is needed.
R12 is not as precise in it's application and for a 60's vintage cooling system, it's simple, it's easy and it's cold...with out needing all the equipment you and I have.
Evacuate..recharge and you are done...(providing it holds a vacuum of course.)
Another thing ...when we started retrofitting to 134A it was dirt cheap....now it's prices have skyrocketed too.
I too have been certified since they started doing certifications in the 70's, and still am. I didn't say you couldn't make 134A cool..I said not as good as R12. I stand by that. I very rarely have come backs and my customers are satisfied with the cooling....As for my personal stuff , vintage iron particularly...I perfer R12, because I can tell the difference....usually 4 or 5 degrees at the duct.
The amount of 134 A "is" critical, as you said, and often guess work when you are just topping off a system, among other times. Many old systems do not have the tags stating how much refrigerant was recommended from the manufacturer...therefore difficult to determine what is 10% less, if that is the method you use.
Dual R12 systems like old Surburbans that use both an expansion valve and an orfice tube...are particularly awkward to just top off.....once retrofitted.
The orfice tube and expansion valve fluctuate out of sinc and the head pressures are hard to nail down.....making it even more difficult to get the proper amount of refrigerant unless you start from scratch with a precise measured charge.
Now back to old cars which is really the topic ..the older they are the more this applies....again in my view.
Even if the 134A would cool as well. (Can we agree to disagree there, without animosity...I'm just stating my opinion) and I "do" agree with your retrofit procedure for the most part... the cost of doing a proper retrofit exceeds the cost of R12 refrigerant, especially if refrigerant is all that is needed.
R12 is not as precise in it's application and for a 60's vintage cooling system, it's simple, it's easy and it's cold...with out needing all the equipment you and I have.
Evacuate..recharge and you are done...(providing it holds a vacuum of course.)
Another thing ...when we started retrofitting to 134A it was dirt cheap....now it's prices have skyrocketed too.
- Thread starter
- #28
Stan & Junk
since I'm still trying to decide which way to go here I have a few more questions........ what if the system isn't a vintage 60's but rather a late 70's (such as a '78 factory system).
would the same logic apply or are there enough differences between the 60's AC systems and a late 70"s AC system to cause a change in anything important?
Also, when I was reassembling the system when putting the car back together I changed out all but two of the O Rings with a replacement set - they are the green ones that Junk mentioned. If I decide to stick with R12 do the green O Rings need to get changed back to the original black style ones?
I understand that IF I decide to convert to R134a I'll expect the shop doing the work to have to go thru the entire system front to back and make whatever changes are needed and replace whatever parts are needed such as Junk described above so while I've always heard that R134A doesn't blow as cold (approx a 3*-5* difference compared to R12) at least I'd know the entire system had been gone thru front to back so it should at least work OK.
IF I decide to stick with R12 do I need to make sure the entire system is just as thoroughly gone thru front to back as much as a conversion simply because it was opened up and I can't expect it to be as simple as the shop refilling it with R12 and saying "here you go, your car is done"?
I should expect that because I opened the system up it would now need to have the entire system flushed, drier replaced, etc, etc whether its a conversion or not so really the labor is really basically the same on either job?
Again, back to what was one of the original questions in the thread, you and Junk gave a pretty good describtion of the R134a conversion although you two tend to disagree on the final performance results but how would I expect the Freeze 12 to perform? Somewhere between R12 and R134a in terms of coldness of the air out of the vent?
Would I need to expect the same requirements of having to have the entire system gone thru just as completely first same as a conversion if I went with Freeze 12?
sorry to drag this out and ask more questions, i just really haven't a clue what I should do.
You know, if EVERYONE all gave the same response of "do THIS" no matter which system "THIS" was it would have made this issue mush easier....... but I should have known not to expect a lot of agreement on any single issue in a forum!
since I'm still trying to decide which way to go here I have a few more questions........ what if the system isn't a vintage 60's but rather a late 70's (such as a '78 factory system).
would the same logic apply or are there enough differences between the 60's AC systems and a late 70"s AC system to cause a change in anything important?
Also, when I was reassembling the system when putting the car back together I changed out all but two of the O Rings with a replacement set - they are the green ones that Junk mentioned. If I decide to stick with R12 do the green O Rings need to get changed back to the original black style ones?
I understand that IF I decide to convert to R134a I'll expect the shop doing the work to have to go thru the entire system front to back and make whatever changes are needed and replace whatever parts are needed such as Junk described above so while I've always heard that R134A doesn't blow as cold (approx a 3*-5* difference compared to R12) at least I'd know the entire system had been gone thru front to back so it should at least work OK.
IF I decide to stick with R12 do I need to make sure the entire system is just as thoroughly gone thru front to back as much as a conversion simply because it was opened up and I can't expect it to be as simple as the shop refilling it with R12 and saying "here you go, your car is done"?
I should expect that because I opened the system up it would now need to have the entire system flushed, drier replaced, etc, etc whether its a conversion or not so really the labor is really basically the same on either job?
Again, back to what was one of the original questions in the thread, you and Junk gave a pretty good describtion of the R134a conversion although you two tend to disagree on the final performance results but how would I expect the Freeze 12 to perform? Somewhere between R12 and R134a in terms of coldness of the air out of the vent?
Would I need to expect the same requirements of having to have the entire system gone thru just as completely first same as a conversion if I went with Freeze 12?
sorry to drag this out and ask more questions, i just really haven't a clue what I should do.
You know, if EVERYONE all gave the same response of "do THIS" no matter which system "THIS" was it would have made this issue mush easier....... but I should have known not to expect a lot of agreement on any single issue in a forum!
gmjunkie
Well-known member
Barry,The green o-rings are just fine there better than the Org.black!! Even if I used Freeze 12 I'd use a ford blue or a smart tube!! I myself use a smart tube on anything that uses a Orifice tube!! It has a variable orifice that changes under different conditions, Like low speed and stop and go traffic!! Also I would adjust the low side cut out switch down to 24-26 lb. you can go as low as 22 lb with out Freez up!! I do have a manual that Tell's me how to figure out how much to use if system dose not have a nomenclature that tells what the correct charge is!! Your system uses 3.75 lb freon or 3.38 lb R134a or Freeze 12 ps If you use R12 I would still put a new drier and a new stock orifice tube! (GM white)
ps If you use R12 I would still put a new drier and a new stock orifice tube! (GM white)- Thread starter
- #30
Junk
Thanks for the additional info.
I still am not sure what you mean by a Ford Blue orifice tube or a Smart Tube but I'm keeping all the info to discuss with whatever shop I take the car to and I'm sure they will know what you are referring to.
Thanks for the additional info.
I still am not sure what you mean by a Ford Blue orifice tube or a Smart Tube but I'm keeping all the info to discuss with whatever shop I take the car to and I'm sure they will know what you are referring to.
G Winter
Well-known member
Ok I am going to throw in another monkey. I thought about starting a new thread on this but figured it pretainded to this one.
Has anyone worked with Red Tek 12 ? I am not sure if it is propane based or not but it does say it is a hydrocarbon base. I found thier site and came up with a composition . It says it is zeotrope. I did purchase some of it but haven't tried it yet. It is suposed to be compatible with both R 12 and 134 a .
http://www.redtek.com/techinfo_refprop.html
http://www.taurusdesign.com/site_wekeepucool1/product_redtek.shtml
the cost is about $8 for 12oz can
Thank you
Glenn
Has anyone worked with Red Tek 12 ? I am not sure if it is propane based or not but it does say it is a hydrocarbon base. I found thier site and came up with a composition . It says it is zeotrope. I did purchase some of it but haven't tried it yet. It is suposed to be compatible with both R 12 and 134 a .
http://www.redtek.com/techinfo_refprop.html
http://www.taurusdesign.com/site_wekeepucool1/product_redtek.shtml
the cost is about $8 for 12oz can
Thank you
Glenn
gmjunkie
Well-known member
Here ya go Barry!! The Smart tube is actually called a VOV ( Variable Orifice Valve) They Work Excellent!!!!! They will make a Retro system, Brass Monkey Cold!! 
Stan's Customs
Well-known member
The green o-rings are best, but either will work with R12...Freeze 12 and 134A will perform about the same. Freeze 12 is mostly 134A.
Unless there has been a compressor failure and the system has debris in the lines etc. ....and "all" you have done is open a system that was functioning beforehand with R12...
A new dryer, new orfice tube, new o-rings at the dryer and orfice fittings and a good evacuation is all that is generally needed before adding the new R12 refrigerant charge.
I generally replace all the easily accessible o-rings when there is no charge on the system ...as a precaution.
In the event of a complete compressor failure the entire system "must" be purged and blown out to remove all debris....this applies to either system....
...which is in essence what has to be done "just" to retrofit to 134A...(to remove mineral oil and replace with Ester oil, and upgrade all the o-rings for the new refrigerant and oil)
The quickest and easiest way...(in my humble opinion), is to replace the dryer, the orfice tube, use the recommended refrigeration that came in the system (R12) , evacuate very thoroughly and recharge. Works every time... and is cold as they come ....
Usually cheaper too, labor cost eat up what little savings there are on refrigerant these days, plus anyone can get the charge right....
....forget Freeze 12....it's mostly 134a, and in my view 134A still needs a larger condenser than R12...at least in this area.
That's my 2 cents.....Good luck...
...and sorry to be a pain Gm...it's obvious you have considerable experience too. We just differ a little....I'm sure we both can freeze the *%^&$ off a brass monkey. Respectfully.....Stan
Unless there has been a compressor failure and the system has debris in the lines etc. ....and "all" you have done is open a system that was functioning beforehand with R12...
A new dryer, new orfice tube, new o-rings at the dryer and orfice fittings and a good evacuation is all that is generally needed before adding the new R12 refrigerant charge.
I generally replace all the easily accessible o-rings when there is no charge on the system ...as a precaution.
In the event of a complete compressor failure the entire system "must" be purged and blown out to remove all debris....this applies to either system....
...which is in essence what has to be done "just" to retrofit to 134A...(to remove mineral oil and replace with Ester oil, and upgrade all the o-rings for the new refrigerant and oil)
The quickest and easiest way...(in my humble opinion), is to replace the dryer, the orfice tube, use the recommended refrigeration that came in the system (R12) , evacuate very thoroughly and recharge. Works every time... and is cold as they come ....
Usually cheaper too, labor cost eat up what little savings there are on refrigerant these days, plus anyone can get the charge right....
....forget Freeze 12....it's mostly 134a, and in my view 134A still needs a larger condenser than R12...at least in this area.
That's my 2 cents.....Good luck...
...and sorry to be a pain Gm...it's obvious you have considerable experience too. We just differ a little....I'm sure we both can freeze the *%^&$ off a brass monkey. Respectfully.....Stan
gmjunkie
Well-known member
No Flaming Here Stan!! On those systems that have both Expansion valves and Orifice tubes I change the Expansion valve to a R134 valve or a Adjustable one and usually the the Low Pressure cut off switch if it is not adjustable!! I've Lived in Florida for 22 years and It gets Hot and Humid there Too, I've Had good Luck with Retro fit systems,except the first 2-3 Wasted allot of Time till I got it Down pat!! I just figured out you just cant cut no corners like you can with a R12 system!! The second time around can Cost you a lot of $$$$,cause it don't pay worth a Darn!! Down there if a Receiver Drier has been open more than 30 min it's Shot!! Ps Stan how much dose a 30# tank of R134a cost you in Texas?? I'm paying $99.00 each last two I bought about a month ago getting Ready for season!!
Ps Stan how much dose a 30# tank of R134a cost you in Texas?? I'm paying $99.00 each last two I bought about a month ago getting Ready for season!!- Thread starter
- #35
Hey Stan and Junk
either of you want to come up and do my car for me?
I can offer some GREAT homecooked meals as payment.......
actually, i have no clue if or how well the system had been working previously or the last time it was working at all.........
No matter what system I decide, R12 or R134 I guess I'll have to have the entire system gone over, dryer replaced, new tubes, evacuated, oil changed out etc just so I know it's correct.
either of you want to come up and do my car for me?
I can offer some GREAT homecooked meals as payment.......
actually, i have no clue if or how well the system had been working previously or the last time it was working at all.........
No matter what system I decide, R12 or R134 I guess I'll have to have the entire system gone over, dryer replaced, new tubes, evacuated, oil changed out etc just so I know it's correct.
birdball
Member
Stan and Junk- iF you use a VOV, does that mean you don't have to touch the POA valve? I have read on some air conditioning forums that to get R134 to work in a R12 system, you have to mess with the low side setting down to 26.5psi (as junkie indicated). In my case, I have an STV in the 66, but I think Barry has a POA in the 65 right?
Do our old corvettes have oriface tube stock, or is this something we would be adding?
This is a really great thread guys! Air conditioning is a complex topic!!!!
Do our old corvettes have oriface tube stock, or is this something we would be adding?
This is a really great thread guys! Air conditioning is a complex topic!!!!
Gary Jaynes
Member
1967 was the first year of the POA. From 1963-1966 they used an STV valve.
Gary Jaynes
Gary Jaynes
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Stan & Junk,
On the way to Barry's house you could stop by and do mine, too...:L
But seriously, since you guys are so into the a/c department, maybe you might know of an original a/c compressor for my '67? There's a replacement unit on there now and I have dreams of going top flight one day. Any help would be greatly appreciated...
On the way to Barry's house you could stop by and do mine, too...:L
But seriously, since you guys are so into the a/c department, maybe you might know of an original a/c compressor for my '67? There's a replacement unit on there now and I have dreams of going top flight one day. Any help would be greatly appreciated...
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