Not all refrigerant oil contains dye. 

And Freon bleeding past the compressor front seal won't carry much oil unless it becomes a major leak. There's only a small oil film at the seal.

It's not like a hose leak where oil being pumped around along with the Freon blows out with the Freon.

Thanks, Tom Hargrave
www.kegkits.com – Electric Brewery Info
www.towercooler.com – Beer Tower Cooler
http://goo.gl/niRzVw - My Amazon Store
www.brew-control.com – Electric Brewery Marketing and Direct Sales
http://www.hackpilot.com/roadkill/ - A little twisted humor

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@GERRY.VANAGON.COM] On Behalf Of David McNeely
Sent: Tuesday, April 14, 2020 11:29 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: found some freon 12 should I recharge old AC

Wouldn't the dye in the refrigerant reveal that leak, Tom?

On Mon, Apr 13, 2020 at 10:58 PM Tom Hargrave <thargrav@hiwaay.net> wrote:

> Could be the compressor front seal. The seal is just an oil film 
> between very close fitting parts.
>
> Thanks, Tom Hargrave
> www.kegkits.com – Electric Brewery Info www.towercooler.com – Beer 
> Tower Cooler http://goo.gl/niRzVw - My Amazon Store 
> www.brew-control.com – Electric Brewery Marketing and Direct Sales 
> http://www.hackpilot.com/roadkill/ - A little twisted humor
>
>
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@GERRY.VANAGON.COM] On 
> Behalf Of Stephen Grisanti
> Sent: Monday, April 13, 2020 11:19 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: found some freon 12 should I recharge old AC
>
>  A Samba thread on R134a conversion from a few years ago involved 
> replacing all the hoses.  He removed them and had a shop put the stock 
> ends on new barrier hose, as I recall, and I think he reported it cost 
> about
> $200 at the time.
> I can never find the link when I want to but it involved an '87 Westy 
> like mine. Stephen
>     On Monday, April 13, 2020, 10:57:02 PM EDT, David McNeely < 
> davmcneely40@gmail.com> wrote:
>
>  Tom, I don't know if your response was meant for me.  I converted to 
> R134a long ago.  Cools great when it gets a new charge, but leaks down 
> over half the summer, and no one can find the leak.  So, I thought -- 
> based on Denis's comment to the original poster, "Aha, might be 
> hoses."  mcneely
>
> On Mon, Apr 13, 2020 at 6:56 PM Tom Hargrave <thargrav@hiwaay.net> wrote:
>
> > If you are considering swapping to R134a, by now the old hoses 
> > should not be an issue because they have been fully saturated with 
> > refrigerant oil and won't leak.
> >
> > But like someone else mentioned the tough part will be to find 
> > someone willing to convert your system. Most AC shops dumped or 
> > upgraded their
> > R12 recovery systems long ago, when the R12 to R134 conversion 
> > business finally went away.
> >
> > You will have three issues with a conversion.
> >
> > 1. A conversion drops about 20% of the system's cooling capacity.
> > 2. The expansion valve is the wrong size and should be replaced.
> > 3. The compressor front seal will leak R134a because its molecule 
> > size is smaller than R12.
> >
> > In other words, to do it right you have to replace the compressor, 
> > receiver dryer and expansion valve and you still lose about 20% of 
> > the system's capacity.
> >
> > You are better off testing for pressure. If your system still 
> > retains any pressure by now, have it serviced and drive it as is.
> >
> > Thanks, Tom Hargrave
> > www.kegkits.com – Electric Brewery Info www.towercooler.com – Beer 
> > Tower Cooler http://goo.gl/niRzVw - My Amazon Store 
> > www.brew-control.com – Electric Brewery Marketing and Direct Sales 
> > http://www.hackpilot.com/roadkill/ - A little twisted humor
> >
> >
> >
> > -----Original Message-----
> > From: Vanagon Mailing List [mailto:vanagon@GERRY.VANAGON.COM] On 
> > Behalf Of David McNeely
> > Sent: Monday, April 13, 2020 3:21 PM
> > To: vanagon@GERRY.VANAGON.COM
> > Subject: Re: found some freon 12 should I recharge old AC
> >
> > Dennis, you said that the original poster's "... hoses are also old 
> > and not designed for R134a."  Some years ago, I had my AC system 
> > (1991 VW Vanagon GL Campmobile) converted to R134a. Based on 
> > extensive investigation before having the conversion done, I believe 
> > everything except hoses was done. The system has never held 
> > refrigerant well since.  It will cool beautifully after a fill, then 
> > drop off in effectiveness until it is kaput about half summer 
> > through.  It has had dye added to the refrigerant, and searched for 
> > leaks, with none evident.  Could the old hoses (originals) be the problem?
> >
> > Thank you, mcneely
> >
> > On Mon, Apr 13, 2020 at 12:54 PM Dennis Haynes 
> > <d23haynes57@hotmail.com>
> > wrote:
> >
> > > FWIW since you are asking this question you probably should not be 
> > > servicing the AC system without some help. Since the system has 
> > > been neglected it is likely to be contaminated with moisture and 
> > > the oil probably also needs to be serviced. The proper procedure 
> > > would be to test for pressure and have anything inside it 
> > > recovered. Good luck finding a shop with R12 recovery equipment. 
> > > Sell the cans. You will need about 1,300 grams to fill an empty system. AC systems are magic.
> > > Even under pressure they somehow manage to get moisture inside. 
> > > Most likely small leaks on the suction side including the 
> > > compressor shaft
> > seal.
> > >
> > > If the system was really empty for a long time then the 
> > > receiver/dryer should be replaced and it would be a good idea to 
> > > change the compressor oil and plan to convert to R134a or one of 
> > > the other "magic" refrigerants out there.
> > >
> > > Then you pressurize the system with nitrogen and ensure it can 
> > > hold pressure, at least overnight.
> > > Then you need to evacuate the system. The longer the better. You 
> > > want to boil off all moisture and other contaminants in the system.
> > > A small amount of moisture can play all sorts of havoc. The 
> > > nastiest is ice crystals blocking the expansion valve and causing 
> > > the compressor to dead head. The
> > > 85 does not have much in the way of safeties and even better 
> > > systems this will often result in blown compressors, hoses, switches etc.
> > > Then charge, by weight. They say R134a should be 80-85% of the 
> > > fill for R12. I find the Vanagon really works best 1,300-1,400 grams.
> > > Don't forget the add the required amount of compressor oil. If 
> > > still some mineral oil in there use Ester. If you really got the 
> > > system cleaned you can use the preferred PAG oil for R134.
> > >
> > > The earlier AC systems are a bit disappointing especially the campers.
> > > Upgrading the condenser to one of the parallel flow universal ones 
> > > help a lot. They also allow for better airflow helping both the AC 
> > > and
> > radiator.
> > > Your hoses are also old and not designed for R134a. Typically 
> > > though the common leak points are the condenser, the compressor 
> > > and the receiver dryer.
> > >
> > > Dennis
> > >
> > >
> > > -----Original Message-----
> > > From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On 
> > > Behalf Of Spencer Allen
> > > Sent: Monday, April 13, 2020 10:36 AM
> > > To: vanagon@GERRY.VANAGON.COM
> > > Subject: found some freon 12 should I recharge old AC
> > >
> > > Found two 1LB cans of R12 in my late uncles garage. My 85 Westys 
> > > AC worked when I bought it 20 years ago but only used it a couple 
> > > of times at first and then not at all. It's probably been 15 years 
> > > since I last used it and it blew cold during that time. Since then 
> > > on the occasions when I turn it on just to run it no cold air 
> > > comes out. I hear this old stuff is really expensive so since I 
> > > have these
> > > (free) cans sitting here I'm tempted to hook up my hoses and 
> > > recharge
> system.
> > > Any thoughts or input on this idea?Spencer85Westy
> > >
> > -----
> > No virus found in this message.
> > Checked by AVG - www.avg.com
> > Version: 2016.0.7924 / Virus Database: 4793/15886 - Release Date:
> > 08/14/18 Internal Virus Database is out of date.
> >
> >
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2016.0.7924 / Virus Database: 4793/15886 - Release Date: 
> 08/14/18 Internal Virus Database is out of date.
>
-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2016.0.7924 / Virus Database: 4793/15886 - Release Date: 08/14/18 Internal Virus Database is out of date.