Author Topic: How to convert from R12 to R134 on a 69 Camaro  (Read 1827 times)

57dv

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How to convert from R12 to R134 on a 69 Camaro
« on: July 26, 2009, 10:25:51 PM »
I have read multiple discussions concerning this and am not sure what is accurate. The front seal on my compressor went several years ago. The system is still sealed and I am preparing to repair the system and am thinking about converting to R134 once the compressor and dryer are replaced.

Is there a documented procedure out there? I read about flushing the system with brake cleaner and compressed air to changing the o-rings and hoses to doing nothing.

Any help would be appreciated.

Thanks,

Dennis

qwertyme77

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Re: How to convert from R12 to R134 on a 69 Camaro
« Reply #1 on: July 27, 2009, 01:03:37 AM »
I'M NO EXPERT, but i talked to a friend about this same thing for my '67. he is part owner of a repair shop and worked for a dealership for a number of years and does a/c work. this is what he said:

The problem with the older a/c systems are the materials used. The hoses and seals for a r134a system are chemically different than ours. while you could do a flush and refill, you will find that you will have to refill the system more often. On a molecular level, 134a refrigerant is smaller than r12. as a result there is more leakage through the rubber hoses and seals. To prevent this you would have to rebuild the system with new materials.

He also cautioned about the r12 direct replacements. (I'm NOT talking about 134A!!!) There have been cases where explosions have occurred because of the flammability of the product. An a/c shop has no way of knowing if you have R12 or one of the flammable r12 replacements when they evacuate a system. As a result he cautioned buying any large R12 bottles (like a bbq grill size) as it could be used refrigerant. As a result I am always looking for unused one pound cans of R12 at garage sales and  I have decided to keep the factory system and keep using R12, but only from the one pound bottles.

Stingr69

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Re: How to convert from R12 to R134 on a 69 Camaro
« Reply #2 on: July 27, 2009, 12:17:55 PM »
I bought a case of R12 in the small cans. $250 if I remember right. You may need a HVACR Lisc # though.

-Mark.

JKZ27

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Re: How to convert from R12 to R134 on a 69 Camaro
« Reply #3 on: August 03, 2009, 02:07:41 AM »
I did a 134a changeover on a 69 a few years back and it works fine. I flushed ALL components with an A/C flush chemical first to remove ALL the old refrigerant oil. The older R12 refrigerant oils are not compatible with 134a. I replaced the receiver dryer, then added the right amount of 134a compatible oil to all the components, reassembled with new o-rings. The biggest problem I ran into was finding a working POA valve, which had nothing to do with the change to 134a. It still works great but It'll never blow as cold as an original working R12 system.

John
69 RS/SS Cortez Silver, L48 MC1
68 RS Ash/Ivy Gold 327EFI M20
79 Z28 Brown LM1 M21
04 SRT 10

57dv

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Re: How to convert from R12 to R134 on a 69 Camaro
« Reply #4 on: August 08, 2009, 03:35:12 PM »
My thanks to everyone for their responses. I'm trying to get more reference material on the internet for more details to combine with the responses.