86 Corvette -difference between R12 and R12a

[Stephen B.]

My 86 needs a bit of freon. Has anybody used R12a?

Thanks in advance.

[Larry M.]

Re: 86 Corvette -difference between R12 and R12a

Stick with R12. Buy it on Ebay. If needed you can either get a #609 license (not difficult) or simply sign a waiver that it will be utilized by a #609 certified technician.

R12a I believe is entirely different refrigerant and may be flammable as well. In the best case, you wind up with a system of mixed refrigerants that no shop will/should accept for any AC work. It may also cause you difficulty with your AC system.

R12 prices are pretty stable right now (around $25/lb) .........and are higher than normal because it is summer. They should not be a significant issue in the future.

R22 for existing home AC systems is now up to $20/lb if you are licensed and buy a 30 lb jug..........(unfortunately) some AC service and repair shops are now charging over $100/lb for R22 installed in your home system.

Larry

[Stephen B.]

Re: 86 Corvette -difference between R12 and R12a

Thanks Larry

[Larry M.]

Re: 86 Corvette -difference between R12 and R12a

Thanks Larry

https://en.wikipedia.org/wiki/HC-12a

Not certain I agree with Wikipedia in all areas of their writeup, but you can at least read what they say and their cautions.

Larry

[Tom L.]

Re: 86 Corvette -difference between R12 and R12a

I'm not familiar with HC-12a, the only hydrocarbon refrigerant that I'm aware of is available is R-1234yf. Might be what you're referring to. It has been embraced in Europe but hasn't found it's way here. There are many internet myths that are associated with it, flammability being one of them. I won't start on the 134a myths but there are many of those as well. If you go to Carlisle there's a vendor that sells it, I've spoken to him and along with my own research I don't see an issue with it.

And Larry, your current R22 cost estimate is well south of the actual cost, TODAY. I no longer buy it, there are suitable replacements at a much lower cost. If you've been charged $100/lb you're being charged fairly. I won't go into the details but refrigerant is a high mark up item in the refrigeration and A/C business.

[Patrick B.]

Re: 86 Corvette -difference between R12 and R12a

Tom -- 15 lb tanks of R22 are selling for more than $800 to licensed techs in my area. What is the suitable replacement? Can it be used to recharge systems still containing R22 or must the system be evacuated?

[Duke W.]

Re: 86 Corvette -difference between R12 and R12a

I have two R-12 cars. Back in the nineties when I regularly attended the SEMA show in Vegas I queried all the AC service equipment vendors about converting to R-134a. Every single one said stick with R-12 at long as it was available and there were huge stockpiles at the time.

For awhile R-12 got pretty expensive compared to R-134a, but the last time I checked it was actually cheaper. The last R-12 cars are now about 20 years old and few are worth servicing, especially if a major repair is required, and there still appears to be plenty of R-12 around, but the biggest problem is finding a shop that still has R-12 service equipment.

So my recommendation is to stick with R-12, which is what I am doing.

Duke

[Tom L.]

Re: 86 Corvette -difference between R12 and R12a

That is to some degree a loaded question. There are probably 8-10 R22 replacements available right now. There are three criteria for choices in refrigerant. Price, contractors choice and application. If you're in the situation that you need to retrofit your system with another refrigerant your contractor MUST recover all refrigerant in the system and based on the refrigerant choice change the oil to insure proper oil return. Unlike our vettes, oil circulates through the system and if it leaves the compressor and can't return bad things will happen. To keep it simple, R407c is the retrofit refrigerant of choice in the A/C world. If done properly it will be as good as R22.

[Joe R.]

Re: 86 Corvette -difference between R12 and R12a

My 86 needs a bit of freon. Has anybody used R12a?

Thanks in advance.

There are a lot of differing opinions on suitable replacements for R12. I believe the least controversial replacement is R134A. To do this replacement correctly, you need to change the oil in the compressor and replace the drier. R134A is readily available at auto parts stores such as NAPA.

This is certainly the easiest and least controversial substitute for R12. Other than the cost of the conversion, the only downside is a theoretical reduction in the cooling capacity of the system (maybe 10% or so), because R134A has a slightly different pressure-temperature curve than R12, and any system designed for R12 will have its set points optimized for R12. Sometimes the controls can be adjusted to match R134A, but even with no adjustments to the controls, most R12 systems will perform okay with R134A.

I went to great lengths to retain R12 in my '67 Corvette, such as becoming MACS certified (via an online, open-book test) so that I could legally buy R12. I have to do all the servicing myself because my local service station no longer has the R12 recovery equipment that they would be legally required to use to service my system.

I also own a 1988 Toyota Supra that was originally built with R12 A/C, but for simplicity I recently had that converted to R134A so that I could have my local service station maintain the system. Overall I think the resulting cooling performance with R134A is pretty similar to the performance with R12. Since I try to spend my limited garage time on my Corvette instead of the Supra, this tradeoff was worth it to me.

If you have just a very slow leak in your R12 system and adding some R12 will solve the problem for a year or two, you might consider just buying some R12 and adding it to your system as needed. While R12 can not be legally sold to someone without MACS certification, it is commonly available at swap meets in 12 ounce cans with no questions asked. Also, the online test for MACS certification is not difficult, and this allows you purchase R12 legally in places such as ebay.

[Patrick B.]

Re: 86 Corvette -difference between R12 and R12a

That is to some degree a loaded question. There are probably 8-10 R22 replacements available right now. There are three criteria for choices in refrigerant. Price, contractors choice and application. If you're in the situation that you need to retrofit your system with another refrigerant your contractor MUST recover all refrigerant in the system and based on the refrigerant choice change the oil to insure proper oil return. Unlike our vettes, oil circulates through the system and if it leaves the compressor and can't return bad things will happen. To keep it simple, R407c is the retrofit refrigerant of choice in the A/C world. If done properly it will be as good as R22.

Can R407c be added to system already containing R22 using the R22 gages and pressures?

[Tom L.]

Re: 86 Corvette -difference between R12 and R12a

Tools are identical except for the built in pressure/temperature (P/T) chart on the gauge face. If you need that feature then buy gauges with that feature. I simply use a pocket P/T chart.

As far as adding 407c to a system that contains R22, that's a no-no. I know that some guys out there do it. I'm not a chemical engineer and EVERY manufacturer of refrigerants advises against it for valid reasons. To properly retro fit to 407c ALL R22 must be removed, filter, all rubber seals must be replaced and all mineral oil must be replaced (95% is the rule but that has been debated), system evacuated and charged with approximately 80-90% of the R22 charge.

That being said, R22 or any of it's replacements are NOT suitable for any cars. We're way off topic. might be better if any questions are asked through PM's.

[Larry M.]

Re: 86 Corvette -difference between R12 and R12a

Tools are identical except for the built in pressure/temperature (P/T) chart on the gauge face. If you need that feature then buy gauges with that feature. I simply use a pocket P/T chart.

As far as adding 407c to a system that contains R22, that's a no-no. I know that some guys out there do it. I'm not a chemical engineer and EVERY manufacturer of refrigerants advises against it for valid reasons. To properly retro fit to 407c ALL R22 must be removed, filter, all rubber seals must be replaced and all mineral oil must be replaced (95% is the rule but that has been debated), system evacuated and charged with approximately 80-90% of the R22 charge.

That being said, R22 or any of it's replacements are NOT suitable for any cars. We're way off topic. might be better if any questions are asked through PM's.

I agree. In addition, just so folks know, the R4xxx series refrigerants are mixtures and are designed to only be added as a LIQUID to your system.

Larry

[Stephen B.]

Re: 86 Corvette -difference between R12 and R12a

thanks for everyone's input.

Stephen