AC - How to tell R12 or R134 (Page 1/2)
runninwideopen AUG 06, 01:51 PM
Hi all,

Still restoring my 88GT. The car sat for 13 years in a barn. I got the blower working. The AC compressor does seem like it kicks on when first pushing the button, and it even seemed like it started to get cold, but then gave up. Hoping it just needs charged.

How can I tell if this car has been converted to R134 or not? My old Fiero had a nice R134 sticker on it. This one has nothing. I'd like to be more certain than just assume it's R12 since it doesn't have an R134 sticker.
sanderson231 AUG 06, 03:06 PM
The only way to be sure is with very expensive equipment that can chemically analyze the refrigerant. A/C repair shops have such equipment because they cannot afford to contaminate their recovery systems with the wrong refrigerant. I would think a shop could ID R-12 but at the least they should be able to ID if it's not R-134a.

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formerly known as sanderson
1984 Quad 4
1886 SE 2.8L
1988 4.9L Cadillac
1988 3800 Supercharged

runninwideopen AUG 06, 03:39 PM
A friend told me that R12 and R134 would have unique port connectors. Is that true for cars that have been converted?
sanderson231 AUG 06, 04:11 PM

quote
Originally posted by runninwideopen:

A friend told me that R12 and R134 would have unique port connectors. Is that true for cars that have been converted?



Yes that's true!!!. R-134a hoses from an A/C gauge set are quick connect. R-12 gauge hoses are screw-on. The R-134a hose connections will look something similar to the male quick connect on an air tool. For sure R-134a gauges cannot connect to a R-12 connection. The major auto parts stores all lend out A/C gauges.

R-134a adapters have to be installed when doing a conversion.

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formerly known as sanderson
1984 Quad 4
1886 SE 2.8L
1988 4.9L Cadillac
1988 3800 Supercharged

[This message has been edited by sanderson231 (edited 08-06-2022).]

theogre AUG 06, 04:41 PM
sanderson231 is true... We'll call this a Sniffer for easy ref...


quote
Originally posted by runninwideopen:
A friend told me that R12 and R134 would have unique port connectors... Is that true for cars that have been converted?

Legally R134 conversion requires test fittings to match R type... In shot you put Permanent R134 "adapters" on R12 High and Low test ports and Label for R134 conversion.

But Do Not Trust fitting used because many simply skip this or worse use illegal Refrigerates that don't have fittings for vehicle use.

Even If "Legal" Refrigerate on EPA SNAP Means Nothing for Vehicle AC.
Legal for cars is DOT/NHTSA Approved is R12 and R134 for old cars. R134 is still used w/ new cars. (R1234yf is legal Only for Vehicle that came with it.)

So If any Sniffer (Standalone or build into Recovery Machine) says anything other then R12 Or R134 then Most places won't touch it. Some might but Bill you Big Time because cost them Big Time to dispose contaminated refrigerate etc.

Many places even then won't touch R12 because don't have machines etc to handle R12. Many dumped old R12 equipment or never had because take space and money for rarely use tools and recovery machine.

Others simply won't touch any old cars, often > about 15 years, or want Big $ because have more problems... Example: If have 1 "rubber" hose leaking you can bet any/all others are leaking now or very soon and car owner blaming the shop on Yelp FB etc that the AC doesn't work again.

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

sanderson231 AUG 06, 06:16 PM
Just to make clarify on "sniffers". You can buy what could be called a sniffer that will find a freon leak. For example at an o-ring connection. These are not too expensive <$100. A sniffer that can ID the type of refrigerant are close to $1000 for a cheap one. Thousands for a really good one.

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formerly known as sanderson
1984 Quad 4
1886 SE 2.8L
1988 4.9L Cadillac
1988 3800 Supercharged

sanderson231 AUG 06, 06:20 PM

quote
Originally posted by theogre:

Others simply won't touch any old cars, often > about 15 years, or want Big $ because have more problems... Example: If have 1 "rubber" hose leaking you can bet any/all others are leaking now or very soon and car owner blaming the shop on Yelp FB etc that the AC doesn't work again.




This is why it makes sense to learn how to maintain these systems in old cars yourself. All the tools are available for loan at the major autoparts stores. A/C supply places will save the ends from your hoses and recrimp onto new hose.

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formerly known as sanderson
1984 Quad 4
1886 SE 2.8L
1988 4.9L Cadillac
1988 3800 Supercharged

reinhart AUG 10, 01:10 PM
I had heard the compressor needs to be changed out when converting from R12 to R134. If that's the case it would be obvious by inspecting the compressor I would think.
steve308 AUG 10, 02:34 PM

quote
Originally posted by reinhart:

I had heard the compressor needs to be changed out when converting from R12 to R134. If that's the case it would be obvious by inspecting the compressor I would think.



Nope, but if the car has been sitting without a charge, installing a NEW compressor is advisable. You will need to change the reciever dryer, orifice tube, (use a variable orifice tube) AC clutch switch and of course use the proper o-rings.

Search is your friend here on Pennocks....You-Tube helps a bit

Good luck.

Oh, never ever ever use a stop leak in your AC!
theogre AUG 10, 04:55 PM

quote
Originally posted by reinhart:
I had heard the compressor needs to be changed out when converting from R12 to R134. If that's the case it would be obvious by inspecting the compressor I would think.



quote
Originally posted by steve308:
Nope,

Actually Maybe... Depends on the compressor. Some R12 compressors hate R134 and leaks or won't last long if converted.

[This message has been edited by theogre (edited 08-10-2022).]