R-12 or 134a: Know the Refrigerant Contents of Your Classic Car’s AC System

We sometimes receive questions from owners wondering what type of refrigerant is in their air conditioning system.  Cars manufactured prior to 1995 originally came with R-12 Freon, a refrigerant that was discontinued due potential ozone damage.  Cars manufactured after 95, and older systems requiring re-charging contain a more ozone friendly refrigerant known as 134a.  Questions about system refrigerants arise when it isn’t clear if the ac system has ever been recharged.  The following customer e-mail is case in point:

I needed to discharge the A/C system on a 1970 SS Chevelle that had a frame off restoration about five years ago.  Is there any way to tell if the system contains 134a or R12? There are no labels or charging adapters installed.  The owner is into original appearance and the rebuilders may have removed any indication of a 134a conversion.

Thank You,

D

If the car has been converted to 134a, law requires placement of a sticker indicating the type of refrigerant added.  Additionally, if this system is a conversion, you should see 134a adapters on the charge ports.

“Do it yourself” type owners aren’t always aware of the sticker requirement and they sometimes ignore this finishing step in the re-charge process.  With this said, even if there was a sticker, it wouldn’t be a guarantee.  Unfortunately, the use of a refrigerant identifier is the only way to determine what refrigerant or combinations of refrigerant are in the system.  Any good facility specializing in auto air-conditioning will typically have one of these in-house and will charge a nominal fee, if any, to check the car to identify the refrigerant.

Do you have questions about converting to 134a or are you in need of the proper port adapters for a refrigerant conversion?  If so, send us an e-mail or give us a call and we’ll be glad to offer additional information.