A/C Assistance
Thread Starter
Burning Brakes
Joined: Jun 2002
Posts: 792
Likes: 2
From: Norcross GA
A/C Assistance
Last year I converted my a/c to R134. It blows at about 38 degrees when it is working correctly. I've had a couples of setbacks that were repaired under warranty. The latest was the valve behind the compressor had vibrated loose and had leaked refrigerant.
I was talking to the guy, of course the guy that did the original work is no longer there, and we were talking about the condenser (the thing in front of the radiator in case I got the condenser and evaporator confused). This was replaced last year with a stock replacement of the original size. He suggested to me that R134 works better with a smaller condenser and that the shops automatically replace them with the R12 replacement due to fit considerations. Has anybody heard of this before?
He has also indicated that they use an oil that is compatible with both R134 and R12 and suggested that he would convert it back for the cost of the refrigerant. When this is done he felt that I would get 32 degree air rather than 38. Any comments on this as well, particularly as it relates to the oil.
I was talking to the guy, of course the guy that did the original work is no longer there, and we were talking about the condenser (the thing in front of the radiator in case I got the condenser and evaporator confused). This was replaced last year with a stock replacement of the original size. He suggested to me that R134 works better with a smaller condenser and that the shops automatically replace them with the R12 replacement due to fit considerations. Has anybody heard of this before?
He has also indicated that they use an oil that is compatible with both R134 and R12 and suggested that he would convert it back for the cost of the refrigerant. When this is done he felt that I would get 32 degree air rather than 38. Any comments on this as well, particularly as it relates to the oil.
Pro
Joined: Dec 2000
Posts: 560
Likes: 0
From: Camino CA
Re: A/C Assistance (Bobchad)
I've never heard that about smaller condensers. R-134a doesn't cool as good as R-12 because R-12 is a much better refrigerant. Ester oil is compatible with both R-12 and R-134a. PAG oil is for R-134a only and Mineral oil is for R-12 only.
Le Mans Master
Joined: Aug 2001
Posts: 7,804
Likes: 4
From: Standing still with all my might Texas
Cruise-In X Veteran
St. Jude Donor '09-'11
Re: A/C Assistance (Bobchad)
R-12 freon uses a mineral oil, and it is not compatible with R-134. When converting to 134 you should always drain the oil out of the compressor, replace the receiver/dryer, and flush all of the remaining components (condensor, hoses, evaporator). The compressor and dryer should then be filled with the recommended amount of Ester oil.
If I remember correctly the problem with using mineral oil with R-134 is that under pressure there will be a chemical reaction between them and acid will be formed that will destroy your compressor prematurely.
I am far from an expert on this subject, but I seriously doubt that a smaller condensor (yes that is the thing in front fo the radiator) would be more efficient than a larger one. An A/C system is a simple heat exchanger, the more contact area you have between the heat source (compressed refrigerant) and the cooling air you have the more efficient you system is going to be.
I am planning to rebuild my engine sometime in the next 6 months, and while I have it out I am planning to replace my condensor with a more efficient one. These are the ones I have been looking at. http://www.ackits.com/index.cfm?fuseaction=Parallel
You might want to contact these people and find out what thier recommendations are.
Then let me know how it all works out :D
If I remember correctly the problem with using mineral oil with R-134 is that under pressure there will be a chemical reaction between them and acid will be formed that will destroy your compressor prematurely.
I am far from an expert on this subject, but I seriously doubt that a smaller condensor (yes that is the thing in front fo the radiator) would be more efficient than a larger one. An A/C system is a simple heat exchanger, the more contact area you have between the heat source (compressed refrigerant) and the cooling air you have the more efficient you system is going to be.
I am planning to rebuild my engine sometime in the next 6 months, and while I have it out I am planning to replace my condensor with a more efficient one. These are the ones I have been looking at. http://www.ackits.com/index.cfm?fuseaction=Parallel
You might want to contact these people and find out what thier recommendations are.
Then let me know how it all works out :D
