C3 (1974) A6 A/C Compressor Conversion

[Jim T.]

Re: C3 (1974) A6 A/C Compressor Conversion

Joe I still have two Corvettes that use R12, so I bought a 30# container of R12 about 1993 and have only used a few ounces to top off. I should be good for awhile. Mayby I should get some R134 to store away.

[D S.]

Re: C3 (1974) A6 A/C Compressor Conversion

Despite all the testimony about R-134A and similar refrigerants being as good or better than R-12 I have found no replacement refrigerant that equals R-12 for maintaining being cold at long stops such as parades, stoplights, and traffic jams in hot Texas summers. R-134A just fails to perform as well under those conditions. I would welcome a refrigerant that would be compatible to our older R-12 systems without aesthetically affecting the appearances. However, I have seen the High/Low side changes on R-12 systems changed over to R-Something Besides. Ain't pretty to see blue and red plastic caps on obviously not original valves where tin plated brass caps used to be on R-12 systems. Another concern is the ever increasing expense to change over to these new 'super' refrigerants.

[Lee S.]

Re: C3 (1974) A6 A/C Compressor Conversion

I went through a similar experience with my '74. I stuck with R12. It can be purchased on ebay. The last time I bought it (3 years ago), I paid $80 for a case of four 12 ounce cans. This is plenty to do a complete recharge. I bought two cases so I can have a spare. As far as being licensed, you can take a course and test online (google R12 license test) or purchase the R12 in the name of the legitimate shop you will use to properly evacuate and recharge the system. Almost any shop will do this. They don't have R12 but they are more than willing to work with yours.

Last point is to have the AC hoses rebuilt before you go through all of this. Usually, they can take your fittings off of the old hose and crimp them on new hose. I learned this the hard way. After having my system charged, the 30+ year old hose burst after being pressurized for about 12 hours. I can tell you with full confidence that there is no ozone layer left in the atmosphere in my garage!

[D S.]

Re: C3 (1974) A6 A/C Compressor Conversion

Hey, I did the same thing by loading up the system with R-12 but I had already gotten new hoses with correct crimps installed. What did I not do? Replace the accumulator (drier). The lines cold sweated and frosted right up to the accumulator then stopped. The accumulator was room temperature as well as the condenser coils. Anyway, I'm not so sure now that I want to drive a big block with AC running with gas prices such as they are.

[Lee S.]

Re: C3 (1974) A6 A/C Compressor Conversion

Hey, I did the same thing by loading up the system with R-12 but I had already gotten new hoses with correct crimps installed. What did I not do? Replace the accumulator (drier). The lines cold sweated and frosted right up to the accumulator then stopped. The accumulator was room temperature as well as the condenser coils. Anyway, I'm not so sure now that I want to drive a big block with AC running with gas prices such as they are.

I also replaced the VIR and compressor the first time around.

I hear you on gas prices. My '74 is a big block automatic. Despite extensive work with insulation and sealing, I can't imagine driving it without AC. The car is in storage now with a full tank of Sunoco Ultra purchased last fall. The gas in the tank has appreciated in value more than my 401K.