As a happy Duracool customer, I'll report that Duracool runs at LOWER
pressure that R134 (or even R12) and gives effectively as good a
cooling as R12 did (and better than R134).

To be legal in the US, systems using R12, must have been converted to
the R134 oils and fittings to properly use Duracool (though Duracool
will work with either type of oil.)

That said, both of the systems I've got running Duracool were converted
to R134 first. I converted the Westy only after the valve got stuck
open on the low pressure fitting and emptied the R134 completely from
the system :(

I had to fix the valve, of course, before evacuating the system and
recharging with Duracool, but the system cools so much better now.

And as Jeff says, A/C repair isn't brain surgery. A/C systems are
actually very simple, and once you get the tools (set of pressure
guages, and maybe a vacuum pump)  it's quite trivial to work on.

On Monday, July 7, 2003, at 01:58  PM, Jeffrey Schwaia wrote:

> After many, many R134 conversions for customers (and a few for
> myself), I
> must disagree.  I've had very good luck with the longevity of these
> conversions.  I always replaced the receiver/dryer, the expansion
> valve and
> all O-rings at the time of conversion.  Additionally, the compressor
> was
> removed and thoroughly drained of any residual oil.  After a lengthy
> evacuation of the system, R134 is added till high-side pressure
> reaches no
> more than 250 psi (that's on a 100 degree day).