Anyone know what's involved in upgrading an R12 LS400 to R134a? Or is there
a better way (substitute gas, etc)

Thanks

You could hear a pin drop when the almighty "ib" <ib (AT) o2 (DOT) co.uk>
addressed his adoring fans with these immortal words:


have a local A/C repair shop check their MACS (I believe it's called).
It lists every vehicle that has R12 refrigerant and what it takes to
convert to R134A.

Some only require seal changes and a complete flush of the cooling
system. Other cars require replacement of the evaporator tank,
compressor, etc. Consequently, it can be as cheap as a $100 or as
expensive as a thousand dollars (or more). But at a minimum, the
seals must be replaced because the molecules for R134A are half the
size of R12 and even the smallest (existing) leak will lead R134A
twice as fast.

Whatever you do, you MUST *completely* flush out the R12 refrigerant
(not just drain), as the two gasses are not compatible and will
permanently destroy your a/c if they're mixed together AT ALL.

Which begs the question, why do you want to convert? R12, although
expensive, is much more efficient at cooling than R134A. If you have
an efficient system with no leaks, I'd stick with the R12.

<kegler (AT) bowling (DOT) net> wrote

You could hear a pin drop when the almighty "ib" <ib (AT) o2 (DOT) co.uk>
addressed his adoring fans with these immortal words:

No it's still available for cars that use it. However, it's very
expensive. It's legal to fill cars requiring R12 but it's not
legal to retrofit a modern a/c system, (if it's even possible), for
R12.

The R12 that's available today is actually reclaimed "dirty" R12
that's been cleaned and recycled. The actual (legal) production of
R12 ceased in Jan 1996, hence the reason that R12 is about 3 or 4
times more expensive per pound than modern refrigerants.

For example a 30lb cylinder of R134A is approximately $200, where
a 30lb cylinder of R12 (CFC12) is almost $500. That's wholesale to a
licensed a/c technician. Expect about a 40-50% markup from there for
consumers. To completely flush/refill an R12 system can easily run
$500 and up.

"ib" <ib (AT) o2 (DOT) co.uk> wrote

used in new applications... at least in the US. Shops are required to
collect (and save) it during conversions, but it CAN be reused. They must
NOT refill it into a system with a leak. The leak must FIRST be identified
and fixed. And if you are at a shop with a unit that is not getting cold,
it is ASSUMED there MUST be a leak. They insert a UV dye into the existing
system and look for leaks. Many times it is just due to seepage at the
component joints over time. It is NOT cheap however; I believe about $50/lb
a couple of years ago.. only to get even more expensive. If an obvious leak
can't be identified, it is pretty much a toss up on the cost of a conversion
or refill (boost). As stated before, a conversion requires no major part
replacements other than some seals. I had it done a few years ago for <
$200, and it is still working just fine.

You could hear a pin drop when the almighty "Jerohm"
<jDrEmLoEhTrE (AT) snet (DOT) net> addressed his adoring fans with these
immortal words:

I agree to everything you said *up to* the point of the last two
sentences. It depends on the make/model of car if it requires a
simple conversion or a complete overhaul. Take the car to a
*reputable* a/c professional to determine if your car can be converted
with just seals or if it requires a major component change. The
critical part is flushing the old R12 *completely* out of the system
before putting in R134A. The oils between the two are incompatible
and in two or three years your compressor will go out *big time*.

I came across these series of articles that outline in greater detail
about the different types of refrigerants and their impact. One thing
to note is that R12 is MUCH colder than R134A and if you can keep the
R12, definitely do so. (Remember when all cars had R12 and you could
actually see frost on the vents?..ah the good ole days) :-)

Anyway, if you want to read more, about two or three articles down on
this page is a section titled:

Air conditioner upgrades: Myth and reality (by Dan Stern)

http://www.allpar.com/eek/ac.html


Although it's about MoPar (Chrysler), the subject material is
universal to R12/R134A air conditioning.

cheers