[Vwdiesel] R12 replacement

[Shirley, Mark R]

Some of the problems with R134 is that it has a lower heat capacity than R12, so 
your system ends up undersized a good bit of the time, which might not be an issue
on some vehicles that are wildly oversized, like my 86 F250, which on R12 could freeze
a side of beef in Texas, and on R134 (I didn't convert it, it came that way) gets OK cool.

Also, the normal oil used in R134 systems is PAG polyalkyl-something, which breaks down
in the presence of chlorine based compounds such as R12, even after cleaning, your R12 system
has these in them.  So the normal retrofit kit uses Ester based oils, which are a pretty poor 
substitute compared to mineral based oils.  Mineral oils aren't miscible in R134, so the conversion
requires changing oils.  So either you use a crappy ester oil which barely works, or you use PAG oil
and hope you got the system clean enough.  Then you have the happy side effects of PAG oil which
is EXTREMELY hydroscopic, and absorbs water like no tomorrow, and the side effect of that is 
acids are formed, and eats your evaporator from the inside out while you cool.  I'm told by industry 
insiders that acid perforation on evaporators is a serious problem with R134 conversion industry, and
sales are brisk.

The reason R12 was used for so many years was because it was a really great refrigerant, and had
comparitively few problems.  It's "alleged" ozone depletion was a good enough reason to see quite a 
few billion dollars change hands to the aftermarket ac parts industry.  I say alleged because the players
involved in a lot of this ban on R12 had conflicts of interest according to my sources, and I've seen enough
counterpointing studies on R12/ozone depletion to raise my doubts as to its veracity.  But whatever, 
we can't change the playing field now, R12 is history, and we are left to fight with the aftermath.

The whole R12 fiasco was enough to make me get certified so I could buy the stuff when I needed it, and
avoid the mess as long as possible.

> -----Original Message-----
> From: James Hansen [mailto:jhsg at sasktel.net]
> Sent: Thursday, March 17, 2005 12:58 AM
> To: vwdiesel at vwfans.com
> Subject: RE: [Vwdiesel] R12 replacement
> 
> 
> Having done some R-12 to 134 conversions in the farm machinery, I have
> noticed no difference whatsoever in operation or function, 
> other than when
> service is needed, the 134 is cheap, compared to the "black 
> market" r-12
> that's still around...  there were guys driving around 
> selling it to shops a
> few years ago like rum runners.
>   Propane, duracool, etc work very well for anyone I know 
> that use them...
> but leaks for them usually, because that's why they are using 
> it in the
> first place- the R-12 leaked out, so you can't really expect 
> the hydrocarbon
> based stuff to not leak either...
> -James
> 
> 
> -----Original Message-----
> From: vwdiesel-bounces at vwfans.com 
> [mailto:vwdiesel-bounces at vwfans.com]On
> Behalf Of slatersfb at aol.com
> Sent: Wednesday, March 16, 2005 8:37 AM
> To: vwdiesel at vwfans.com
> Subject: [Vwdiesel] R12 replacement
> 
> 
> DURACOOL claims that their product cools 35 % better than 134a, and
> marginally better than r12. It is also reasonable priced and 
> requires no
> modifications for install. I just bought 3 cans & will try 
> soon. 134a really
> doesn't work very well compared to r12, even in systems 
> designed for it.
> Also, there are some threads about 134a causing testicular 
> cancer! Given the
> choice, I'd prefer to go out in a propane fireball.
> And I'd be happy to help your dad get rid of his r12 stockpile.
> 
> Bob in NY
> 
> ********************************
> 
> 134a isn't that much harder to install. I've not done it as I 
> don't have all
> the tools, but Dad has rolled over his fleet to it and as 
> long as the system
> remains intact (my '85 has a blown evaporator), it works fine 
> without having
> a flammable gas in the cab. If I recall correctly, it's just 
> some fittings
> and a new receiver/dryer. Toolwise, you do have to have a new 
> set of gauges,
> or at least new hoses for your old ones. Dad converted all of 
> his cars even
> though he was still sitting on a stockpile of R12. Doesn't 
> even know what to
> do with it now. Prices dropped because everyone's converting.
> -Shalyn
> 
> Sandy Cameron wrote:
> 
> >New thread for old volks.
> >Summer is comming.
> >
> >Have a look at (google ) duracool, avail. in both Canada and USA.
> >
> >Basically, it's propane with some additives.
> >
> >I think I'll try it in one of the 87's if I can find enough 
> of the hoses to
> >put the system back together
> >
> >All standard disclaimers apply.....
> >
> >Sandy
> >
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