Pelican Parts Forums - How to tell if car is R-12 or R134?

Pelican Parts Forums (http://forums.pelicanparts.com/)

- Porsche 911 Technical Forum (http://forums.pelicanparts.com/porsche-911-technical-forum/)

- - How to tell if car is R-12 or R134? (http://forums.pelicanparts.com/porsche-911-technical-forum/291008-how-tell-if-car-r-12-r134.html)

Quote:

Originally posted by niner11
Jim, I don't want to get too far off topic but I was wondering if you might be able to come up with numbers for some of the other choices we have for refrigerants.

I know there is Freeze 12, HC something, etc. Knowing that there is no holy grail of refrigerants is there anything else out there that makes sense to use.

BTW, I like the idea of delivering pizza in the 911. I could write off an entire Griffiths setup.

Thanks, Chuck

Here's the link to the EPA site that lists the alternative refrigerants that they have determined are legal to substitutes.
http://www.epa.gov/ozone/snap/refrigerants/macssubs.html
And this is a link to a comparison done on several of the alternatives.
http://www.ackits.com/testresults/alttest.pdf
Interestingly, they don't seem to perform any better than R-12 or 134a.

A 26 year old car with unknown refrigerant could have practically any refrigerant in it...who know for certain unless you analyze the stuff? What it should be and what it is are two distinctly different things.

My 78 SC had a conversion done by the PO in the 90's. It had R-12 in it. I put MP-39 in it last year, and noticed no difference. R-134a is a better refrigerant, if you're set up to use it, as Jim stated. If not, the costs to convert may not be worth it.

Edit: Hers a link to MP-39. Notice it is for stationary equipment. I tried it in the car anyway, because inquiring minds wanted to know.

http://www.dupont.com/suva/emea/products/suvamp39.html

Pat

Re: How to tell if car is R-12 or R134?

Quote:

Originally posted by SlantnoseSD
Without having to take my car into the shop, how can I tell if my car has R-12 or has been converted to R-134?

Slanter,

One easy method to determine if the vehicle is using R134a vs. R12 is to look at the refrigerant service ports on the a/c system. On the 911/930 they are located compressor.

A vehicle using R12 will have a "schrader" type valve, which has a thread on the outer diameter. Vehicles using or converted to R134a will have an adapter attached to the schrader valve stem with threads on the inner diameter.

<center>
http://forums.pelicanparts.com/uploa...1151756088.jpg
</center>

In many instances you may or many not find a sticker/label indicating the type of refrigerant.

And be aware that, though not a common occurence (but we have seen everything), cars converted from R12 to R134a sometimes do not have R134a charge port adapters (difficult to do but there are hackers out there), and/or sometimes a car may have a refrigerant other than the traditional R12 or R134a.