Re: R134 conversion fittings

["jtrealtywebspannet" <jtrealty@xxxx>]

Without getting into an argument about whether you should convert to 
R-134a or not in any case although the conversion adapters will 
depress the shrader valve best practice is to remove the existing 
valve cores. The reason being is that to vacuum or charge the system 
with the cores in place is difficult and time consuming. Since when 
converting you will evacuate the system and recharge it is easy to 
remove the valve cores. In normal servicing of automotive A/C systems 
with R-12 most techs will use a valve tool to temporarly withdraw the 
valve core out of the way. On R-134 systems with the proper 
quick-connects there is no longer a need to do that so it makes no 
sense to leave the valve cores in there. If there is a dimple inside 
the dust cap that can depress the valve core you have the wrong dust 
cap and it should be replaced. (someday someone may notice the cap is 
loose and tighten it up!)
There is an alternative to R-134a. I have had a lot of success with a 
drop-in replacement known as R-414. It is a blended refrigerent 
compatable with the lubricant for R-12. System pressures run very 
close to R-12 and the system can be topped off twice without upsetting 
the blend. It is best to change as much of the old refrigerent oil as 
possible but that is always good advice. My longest experience has 
been 6 months but the system blows colder then when using R-12, in 
fact when filling the recomendation is to only use 80% of R-414 for a 
full charge. It only costs about $12 lb as compared to R-12 @ $60 lb 
and you only need 2 lbs. It is compatable with all of the seals and 
"O" rings. When changing to R-134a you are supposed to replace ALL 
seals and "O" rings in addition to installing conversion adapters and 
oil and a big label indicating the conversion. You only need the label 
when changing over to R-414. Stick this post in the FWIW dept. BTW 
only an EPA licensed A/C Tech is supposed to do a conversion or remove 
the R-12.
David Teitelbaum
vin 10757



--- In dmcnews@xxxx, "content22207" <brobertson@xxxx> wrote:
> I know all about R134 conversion fittings. I've got 5 on various
> vehicles of my own, not counting all the other cars I've assisted.
>