A friend has been filling R12 systems on cars with R134a and says
there is no need to evacuate out R12, he has done it for years on many
cars. Is he lucky to not of had his friends cars damaged or can I just
put in R134a in my R12 system without evacuating out R12.
i was told always remove the R12, evacuate the system then add R134a
and AC oil.
When a system loses gas it looses oil too. Not replacing the oil can
destroy the compressor and if it disengrates thats basically the end of
No, it is not automatically in there. If you look on the can some
have it some don't, and you can buy just the oil as well.
On Sun, 28 May 2006 18:32:04 -0500, email@example.com (m Ransley)
Hopefully someone with more expertise wil post, but certainly the two
are not compatible as they act under different pressures.
For my 2 cents I think your friend has been lucky. Lets face it, how
does someone determine their air conditioner needs help - when it's
not cooling, usually at all. How many people do you know that say "I
put a thermometer up to my a/c outlet and the air is 3 degrees warmer
than it should be". Usually it's not blowing cold - e.g. out of R12.
I have successfuly recharged empty R12 systems with R134 without
replacing any parts. It is kind of silly, since I still don't
determine what is wrong, but it's not in my daily driver so I don't
worry. In addition it is not as efficient as swapping out the
appropriate parts (and leaking ones...), but it will work at least
decently. It has to be "under charged" as I believe you only use
about 80 percent as much R134 pressure as you would R12. Even if you
don't have the proper manifolds for measuring all of that the kits
come with a small guage that does the trick.
Bottom line is you would not properly recharge a system if you don't
create a vacuum in the system first, and if you create a vacuum I
believe you would have evaculated all of the R12.
Finally, the oil used in R12 is not compatable with R134 so the system
will fail sooner rather than later, if you don't evacuate that R12 oil
and put in the proper oil.
On Sun, 28 May 2006 17:12:54 -0500, firstname.lastname@example.org (m Ransley)
The EPA doesn't allow mixing refrigerants. To mix them violates
134A is not compatible with the old compressor lubricating oil.
Your friend may make AC that blow cold air, but he's also risking fine
Christopher A. Young
You can\'t shout down a troll.
This procedure was listed on Interdymanics web site after R12 was
discontinued. They make the freon. For conversion to R134A their
1. Vacuum the system removing all R12 and check for leaks.
1a. Turn A/C on high setting.
2. Insert one can of R134A oil charge.
3. Bring system up to normal level using R134A.
3a. Compressor should start turning.
4. Check for leaks.
I've used this system for many years with no problems. Actually I still
use my R12 gages on the R134A can. At your hardware store in the gas
fittings you will find an adapter that fits on the R134A can piercer to
the R12 hose. As the pressure on the low side tends to get near the
normal level I monitor the temperature. When it gets to the normal cool
setting, I quit adding. If you might not be the next person to add more
freon make sure you indicate with a label somewhere under the hood that
it's now R134a since you can't go backward to R12. If anyone has any
problems with this method, look on Interdymanics Web site.
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