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Hey Fellas...I need some advise in order to convert my AC from R12 to 134...all seals/gaskets are exchanged, ( btw..which one needs the supplied O ring???).  retrofit kit installed...about to extract contaminants and old oil...but...the conversion adapter on the low side does not allow any equipment to be installed - simply, because there is no room to do so anymore! ( I would have to take out the radiator or bend the line...) so..

WHICH elbow adapter does actually work with our old AC??? I need answers fast because I have to drive around in 3000 degree heat in Georgia...no fun at all.....here you go: https://www.amazon.com/s?k=r12+to+r134a+adapter+elbow&s=review-rank&qid=1627619986&ref=sr_st_review-rank

Edited by shelbyone
addition (see edit history)
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It's even HOTTER in Arizona!  No help available here with your AC Conversion. I use to send cars needing that to a CERTIFIED PROFESSIONAL AC Shop.

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My advice would be don't, but it's too late for that. Mine was converted when I got it but I still use R12 in my 750iL. R12 is noticeably colder and less likely to leak because R12 molecules are larger than R134 molecules. If I run the AC and then park on a really hot day, and then fire it back up after condensation forms in the vents I can make it snow in the BMW when the condensation freezes and blows out of the vents. Just like the old days. I got the EPA 609 certification so I can legally buy and use R12 and I just watch ebay and Craigslist until I see some for cheap. 

Edited by 2Shelbys (see edit history)
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The pictures above show modified lines. That system has new hose that is rated for R134. Using R134 in our old R12 systems almost always results in a leaky system. A lot of it has to do with the hoses just being old, but also what 2Shelbys said as well. There are also other alternatives to using R134. Some are controversial, but they DO work (like air duster propellant or even propane)..the trick is getting the pressures right. I doubt anyone here would actually use propane, but just to ease people's minds, there isn't a lot of it in the system, and if it does happen to ignite, it goes "POOF", not "BOOM". I was weary about it too, but then I  saw somebody test it, just to see what would happen...put my fears to rest. 

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  • 3 weeks later...
Posted (edited)

update....called 7 shops; they all refused to work on it..another shop actually wanted to and insisted on ordering a new hose ( high site) that turned out to be for a Le Baron....and did not fit. they did evacuate the system, it is sealed and holds pressure. next shop said; we could do it..we just do not know how much PAG oil to use and we dont have it....it is an endless story and it drives me insane...why T$& F*$& is nobody able to do this simple conversion??????

does anyone know the specs on how much PAG oil the system needs? and how much refrigerant?

and IF all the hoses can be found somewhere? because Rockauto and everybody else do not carry them..

 

Edited by shelbyone
typo (see edit history)
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I wouldn't use the PAG oil unless every part of the system is totally cleaned out.  Ester oil would be the better choice since it can handle being mixed with some of the old r12 refrigerant and mineral oil, the PAG oil cannot. The sites I just looked at recommend no more than 5 or 6 oz of oil since some of the old oil will be in the compressor, some in the dryer, some in the condenser/evaporator, and maybe 10% in the lines. Multiply the charge of R12 X .9 then subtract .25lb and you should be very close unless you want to look up the actual charts that list this, I'm surprised the a/c shop didn't look this up, too much 134A will make the system cool LESS without upping the areas of the condenser/evaporator and capacity of the compressor.  

R12 to R134a Charge Conversion Formula (pounds only)

A charge level between 75% and 85% is recommended when converting from R12 to R134a refrigerant. If no conversion information is provided, there is an easy formula to calculate the difference in charge level. This works when the R12 charge specification is listed in pounds. Take the R12 charge specification and multiply it by 0.9. Then, subtract that result by 0.25 pounds to get the proper amount of R134a charge.

Formula: (R12 Charge Specification x 0.9)  0.25 lbs. = R134a Charge Level

As an example, let's say the R12 charge specification is listed at 2 lbs. You would do the following:

Example: (2 lbs. x 0.9)  0.25 lbs. = 1.55 lbs.

This indicates that an R12 charge level of 2 lbs. converts to an R134a charge level of 1.55 lbs.

R12 to R134a Refrigerant Charge Conversion Charts

While the formula above is helpful, you might be strapped for time and need an answer quickly. Below is a PDF of tables that show R12 to R134a refrigerant charge conversions in pounds and ounces:

R12 to R134a Conversion Tables – Pounds & Ounces

I did the conversion a long time ago in my 79 T-top Cordoba with ester oil, the old hoses, and leak sealer in the 134A refrigerant and drove the car with cold A/C for almost 3 years until I sold it. I don't know how much longer it was working like that but I didn't care.

Edited by ghostymosty
added Cordoba comment (see edit history)
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10 minutes ago, ghostymosty said:

I wouldn't use the PAG oil unless every part of the system is totally cleaned out.  Ester oil would be the better choice since it can handle being mixed with some of the old r12 refrigerant and mineral oil, the PAG oil cannot. The sites I just looked at recommend no more than 5 or 6 oz of oil since some of the old oil will be in the compressor, some in the dryer, some in the condenser/evaporator, and maybe 10% in the lines. Multiply the charge of R12 X .9 then subtract .25lb and you should be very close unless you want to look up the actual charts that list this, I'm surprised the a/c shop didn't look this up, too much 134A will make the system cool LESS without upping the areas of the condenser/evaporator and capacity of the compressor.  

R12 to R134a Charge Conversion Formula (pounds only)

A charge level between 75% and 85% is recommended when converting from R12 to R134a refrigerant. If no conversion information is provided, there is an easy formula to calculate the difference in charge level. This works when the R12 charge specification is listed in pounds. Take the R12 charge specification and multiply it by 0.9. Then, subtract that result by 0.25 pounds to get the proper amount of R134a charge.

Formula: (R12 Charge Specification x 0.9)  0.25 lbs. = R134a Charge Level

As an example, let's say the R12 charge specification is listed at 2 lbs. You would do the following:

Example: (2 lbs. x 0.9)  0.25 lbs. = 1.55 lbs.

This indicates that an R12 charge level of 2 lbs. converts to an R134a charge level of 1.55 lbs.

R12 to R134a Refrigerant Charge Conversion Charts

While the formula above is helpful, you might be strapped for time and need an answer quickly. Below is a PDF of tables that show R12 to R134a refrigerant charge conversions in pounds and ounces:

R12 to R134a Conversion Tables – Pounds & Ounces

I did the conversion a long time ago in my 79 T-top Cordoba with ester oil, the old hoses, and leak sealer in the 134A refrigerant and drove the car with cold A/C for almost 3 years until I sold it. I don't know how much longer it was working like that but I didn't care.

thank you so much for this detailed clarification - I can def. work with that!!!!

looks like I am going to send "coldhose.com" my hoses to redo them, including repositioning connectors.

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