Posted by Vegas on September 17, 2001 at 16:30:13: via: or 205.188.200.33
In Reply to: Re: Question for George Goble /George is not around posted by Gil on September 17, 2001 at 13:31:56:
2 oz IS NOT ENOUGH OIL FOR THE SYSTEM.
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So, if I discharge system, change dryer and pull a good vacuum is the flush and oil change needed?
Yes,
You want to get the PAG oil that has the moisture in it out of your system.
Fill the compressor with POE oil and turn it several times to flush out any remaining PAG OIL.
I have to trust your advice and will flush and get PAO if you recommend, but with the DRY PACK I was hoping to avoid at least some work (this is on my own time and weekends are pretty short!)
There's not that much dry pak in cooltop and moisture and refrigerants don't mix.
Don't take a short cut because you may just have to do a whole new install.
.
In just a few months the tubes in the coil will start to be eaten from the inside out and thats why I suggested flushing everything.
POE oil will let go of moisture and any small amount left (IF ANY) the dry PAK will take care of.
Pull the vacuum from both LO & HI sides
Two more maybe silly questions:
1) Will PAG oil completely vaporize if the vacuum is left on long enough or does it leave a residue?
If the pull of the vacuum is strong enough the oil will start to boil off before the moisture.
2) This is for information only, I know it would not be legal in the USA, but would be useful info if I move to Mexico. If I flush the system and use a new dryer could the system be filled with R-12 for better performance? Are all the hoses, seals, o-rings and stuff compatible with mineral oil and R-12?
You'll have to go to a R-12 dryer.
The R-12 "O" Rings are OK if you used the light green rings.
The dark green and blue rings are of the neoprene material.
Yes you can move to Mexico but you have to do a complete retro back to R-12.
Below is the letter from George.
The parts in quotes >> are what the hard core 134a guys are saying.
Unquoted parts are from george.
I was tired of seeing George getting bashed after all the help he gave and thats what prompted this letter.
I sent you a short note direct.
Let me know how you make out.
Vegas
Again, Thanks for your time,
Gil
>There are only two O.E. approved refrigerants and yet SNAP has >approved
>over 25 different freon replacements.
>However, SNAP does not do any testing of these freon in systems
>to determine their useability in automotive
>systems. Go to this site and verify if you doubt this
>information:
>http://www.macsw.org/macs.asp?mfurl=training.html
>
>R134a and R12 is recyclable in the field and therefore is overall
>a good choice for both satisfying the customer and
>the environment. Test data for 134a is readily available for
>a multitude of vehicles. The various other refrigerants don't
>have the same test data- MACS is currently holding AC information
>clinics here in California regarding the new BAR
>regulations and blends. From what I've been told and I'll find
>out specifically tomorrow when I go to one of their
>clinics, they are very harsh on the blends because of
>fractionation.
True blends do lose some performance when they leak (fractionate),
however, some blends, such as R406A (Autofrost) and R414A
(then Chillit), were EPA tested in leaking cars in a controlled
experiment, and compared to R12, R134a, and other blends. With
a given amount of charge loss, R406A/R414A still out performed
all the others. ALso when leaking R406A/R414A systems have fractionated
due to leaking and were then "topped off" (with same refrigerant),
yes there was a performance loss, but only 5% or so, and hardly
noticeable. Even with the fractionation/topoff performance loss,
they still outperformed R12 and esp R134a systems and other blends.
So MACS is correct about fractionation and performance loss, but
they dont mention that the loss is so tiny, that is not noticable
and still outperforms R134a.
>
>How does the refrigerant transport the lubricant after it's
>fractionated? Find that data somewhere on the blends.
>Why doesn't O.E. use them.
R406A/R414A still transport their lubricant fine (mineral oil).
Ask why MACS and the OE's just push "PAG" oil only? OEs fight
tooth and nail against POE (ester) oil for R134a retrofits. MACS
and the OEs argue that PAG is a better lubricant than POE, which is
true, but not by much, considering that most auto A/C compressors
only run a few months total over their entire lifetimes.
The stationary HVAC industry (for R134a and HFC refrigerants)
gave up on PAG oil back in 1992 or so and went with POE (esters),
and only in metal cans (to stop moisture coming in as plastic
bottles do). POE oils only absorb moisture 10-100X more than
do mineral oils used by R12 (and Autofrost). PAG oils are more like
1000X or more moisture absorbing. PAG oils (except daphne or
expensive double end capped) are extremely sensitive to chlorides
(small amounts of R12 or HCFCs or even coatings on pipes left
over from R12). POE can tolerate these. Why do you think OEs
and MACS want R134a retros to use PAG? so the chlorides can
make them fail quicker?
Do GM and MACS give tech the training that PAG oils can
suck in moisture upto 10,000X more than mineral oil? How about
almost all replacemnt R134a dryers having plugs that dont seal tight?
Do you hear them Suck or blow pulling out the shipping plugs?
If you dont hear them suck or blow, then plugs are probably not
air tight and they "breathe" in the warehouse as the atmosphere pres
changes and become water logged before you install them. Many
PAG oils boil (in a vacuum) before the water boils, so pulling
a vacuum will not dry out wet PAG oil systems like it dried out
mineral oil R12 systems.
The way large numbers of 134a evaporators are failing "right after"
the 3 year warranty is over seems to suggest many of these 134a
systems started life with 100ppm or more (intentional???)
of moisture in
them or more, slowly forming HF (acid) which eats away at the evaporator,
timed so that it fails just after the warranty. The standard for
refrigerants is 10ppm moisture and systems with 10ppm or less
moisture will run for many years and have no inside corrosion
or acids forming, even with PAG oil and R134a.
Now after your evaporater eats thru and leaks, you go get it serviced
by a "compentent MACS shop". They go by the book,
and clean up the system,
flush it with 141b solvent (contains chlorinated R-141b!), new dryer,
(that is most probably all ready wet), new evaporator, and fresh
GM PAG oil. They pull a vacuum for an hour or so which removes the
air, but not much of the moisture, recharge with R134a and you are off.
That new GM PAG oil is in a plastic bottle (remember that HVAC
industry went to metal cans for POE oil, that is 100X less moisture
grabbing than PAG). This replacement PAG oil is probably between
800 and 1000ppm moisture, right out of the unopened bottle, and will
climb to over 4000ppm if left exposed to the air for any significant
length of time. See URL www.autofrost.com/wetpag.pdf for a lab report
from Integral Sciences, the premiere refrigerant analysis testing
standards lab. It shows new unopened bottles (plastic) of GM and
Delco PAG oil at over 800ppm moisture! One had might as well urinate
into the system before closing it up with that much moisture.
Now in a couple months, all that moisture has generated enough acid
to fail the condenser or maybe the evaporator again. Customer
is screwed again.. and so this just repeats no matter how good the
shop is at fixing it or even with "proper" procedures..
It is damn near
impossible to ever get a R134a system dry again with PAG oil...
AFter market guys often use POE oil (less moisture absorbing) or
PAO (ROC-OIL - polyalpha+ is acsource.com's brand of this oil) from
OZ that appears to be mineral oil based and somehow claims to be
enough miscible with R134a (and all others) to return to the compressor.
Other solutions are to use Cryo-Chem's Tune-air kit, that contains
"Dry-Pak" (SS02A) silicone dehydrant, that chemically reacts with
the moisture and converts it into harmless silicone oil so it will
not take part in the acid forming reactions and cause corrosion.
"Cooltop" (GHG-X8) refrigerant incorportates Dry-Pak for this reason.
But going to a Dealer or MACS shop, will most often get you loaded
up with WET PAG oil, and failing again after less than 6 months,
with $1500-$2000 bill each time.
Dupont originally wanted to make R-134, not R-134a, another "isomer"
of tetrafluoroethane which was MISCIBLE in mineral oil and would have
worked in old R12 cars and new R134 cars without creating a crisis.
The "committee of 11" voted 8-3 (car OEMs and chemical co.) to kill
R134 and make R134a instead back in 1989, so that stable mineral oil
would not work and special (I.E. moisture grabbing life limiting PAG
oil could be developed and used instead). Dupont even had developed
and patented a "fluorinated mineral oil" that was stable like mineral
oil and would work with R134a! MACS and the establishment seems to
have stopped that also.
Senior Fellow Chemist Don Bivens @ Dupont
invented a series of blends called MP39, MP66, MP52 that became
known as R-401A / R-401B / R-401C comprised of R22/R152a/R124. Although
they did not carry mineral oil well (this was stated upfront),
they did work very well in alkylbenzene (AB) oil, (brand zerol), that
is a highly refined form of mineral oil and unlike PAG/POE is a
stable, non moisture grabbing oil. R-401C (used) to work fine in
85% AB / 15% mineral oil, so you didnt have to drain out all the MO.
MACS and the Auto industry raised so much hell
and issued an edict that
no chemical company could make a non R134a refrigerant or
a blend component or sell non R134a to third parties for resale
to auto industry...or they would be boycotted on their entire
product line (like paints and plastics). Dupont gave in and
said "yes sir", and took MP52/R401C off the US market! it was
even EPA approved at the time. Atochem did not submit FX-56
(R-409A) to EPA SNAP for MVAC approval,only HVAC.. It is another good
automotive (but illegal now) refrigerant in MVAC if used with stable
AB oil. MACS went as far to tear up papers from me and others
such as Dupont from the 1991 Halon and CFC alternatives Conference
after the EPA had accepted them for publication. Any paper that
wasnt pro R134a or PAG oil got killed... and hence they became the
"only" solution...
MACS and the auto industry have now achieved their goal...
You are supposed to buy a new car every 3 years now if you
want your A/C to work. Once it goes over 3 years old it
will soon become "unservicable" or very expensive to keep running
if it is a R134a system and using PAG oil like they want you to use.
Aftermarket compressor rebuilders did just was MACS told them to
do.. Fill the rebuilt compressor with PAG oil... and the plugs
dont seal, so when it sets in the warehouse, just like the dryers,
they "breathe" and suck in moisture as the weather changes.. in
fact so much moisture into the PAG oil, that the compressor is
rusted stuck before the DIY mechanic buys it to install in his car...
Ask EVAPCO about that one..
>
>I know of several fleets that are perfectly happy with blends
>but I don't think that we need 25+ refrigerants floating
>around in the market place when each one is supposed to have
>unique fittings and seperate recovery systems. Let's
>see Mr. Customer, your bill for just checking your AC system
>has gone from 1 hour of diagnostic time to 10 hours
>so that I can pay for all of the seperate recovery machines I
>have in my shop.
EPA "requires" unique fittings, and recovery systems for blends
since MACS lobbied that to the EPA in order to impede blends
as much as possible. MACS also lobbied in recovery/recycle of R-134a
and the need for more recovery equipment (illegal to vent) to
the EPA, even though R134a has zero ODP (no ozone depletion).
Computer "duster" cans are just R134a and they are legal to vent
by definition. Could it be that Ward Atkinson's (tech director of
MACS) good buddy, Art Hobbs, happened to work for Four Seasons
at the time, needed an excuse/law to be able to sell
everyone a 2nd recycle/recovery machine for R134a, right after
they had sold them one for R12? Computer duster cans of R134a
are legal to vent, but why not R134a for a car A/C?
>Or I could just vent it to the atmosphere and hope that the
>EPA doesn't fine me the $15,000 if they catch me. Or I'll
>incinerate it locally, which is also environmentally friendly?
>
What if you hooked up a hose to you R134a car and blew it off
and used that to dust off your computer keyboard and shop?
Just equiv to two "dust off" cans from Sams club?
>When at all possible use the freon that came if the vehicle
>as long as it's cost effective. If not then your best
>alternative for cooling and lubrication is R134a because
>it's safe and easily serviceable by shops everywhere.
New cars are puchaseable everywere also!
--ghg