Alan,

I changed mine over to Freeze-12 last spring.  It is composed of 80% 134A
and 20% something else.  Straight 134A operates under a lot higher pressure
than R12.  Freeze-12 is in between.  Have the AC tech pull a good vac, add a
little ester oil (for the 134) and in theory add 80% of what the R12 charge
would be.  Using gages for pressure is best.  I did not change any O rings,
receiver/dryer, or anything else.  My AC cools just as good as it did with
the R12 (cold air).

The only difference I have noticed is that I have to keep the Ac switch
thermostat turned up a little higher than with the R12.  Because of the
pressure differences the compressor cycles off and on a little more often.

Ken Wilford convinced me to use Freeze-12 and knows a lot more about it than
I do.

Randy Herd
86 GL Weekender
68 Kombi
98 Jeep Cherokee

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