On Sun, 27 Aug 2006 23:48:57 GMT, aarcuda69062
> wrote:

>In article >,
> Olde Chrysler > wrote:
>
>> Refrigerant containing "dye" is for lamers. It causes more problems
>> than it solves, including hose and seal deterioration, gumming up of
>> Schraeder valves, plugged expansion valves and on and on. Don't use
>> "dye" refrigerant.
>
>Cite?
>Many OEMs install system dye at the factory. <snip>

Experience, for one. Back when Du Pont came out with a "leak finding"
dye, service bulletins started flying around in the refrigeration
industry about these problems. Another big drawback is that is dyes
the oil, so you can't do a visual quality check, as well as makes a
general mess of the machine inside. There are some cites about this
in a couple of auto AC forums, but I'll have to dig them up again.

It's quite possible that newer dyes don't have the problems of the old
stuff that was used in halide refrigerants before 134A, but I've never
used them, having been warned off years ago.
>
>> Poop Boys sells and promotes that crap, I believe,
>> so they can sell more compressor swap jobs out in the shop.
>
>You're confusing dye with sealant and O-ring conditioner.
>
>> The only
>> way to do a good leak test is with a proper halide detector. Small
>> leaks may need application of dry nitrogen to boost system pressure to
>> find them.
>
>Actually, R-22 and pressurizing to 75psi or so with Nitrogen
>works quite well and is 100% acceptable with the EPA. <snip>

Yes, it is, and since the 22 molecule is smaller, it makes small leaks
for 12 easier to find at lower pressures. A good trick to use for
those "half pound a year" cars.
>>
>100 torr? You're kidding right? <snip>

No, I don't proofread! My mistake. Any reasonable AC service pump
should get down to <100 microns easily. A hi-vac like an old Kinney
(my favorite) will do a lot better, but then you start boiling off
volatiles out of the oil if you pull it down much below 20 microns for
awhile. With hi-vac hose and fittings, the old Kinneys would be able
to pull as low as 5 microns or less, depending on the volume of the
enclosed system. Most standard guage sets (the 4 valve
Imperial-Eastman's an exception) won't hold that low a vacuum, and
neither will the hoses attached to them.

For portable use, I have an old Sargent-Welch, which years later was
reincarnated into the ubiquitous Yellow Jacket pump seen everywhere.
It's good for 20 microns at blank-off, and my thermocouple usually
sees 30 on a barrier hose car AC system...for awhile, anyway. Pulling
a good vacuum is probably one of the most neglected aspects to car AC
service that I'd seen. Many still believe in the old "well, the
compound guage says 30"....must be done!" routine.