R134 conversion fittings

["content22207" <brobertson@xxxx>]

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.

The original R12 shrader valve remains in place. The adapter actually
presses on this valve (it's nothing more than a glorified pin within a
quick connect housing). The cap has a threaded dimple because the
threads are INSIDE the fitting.

I'm just cautioning people to be aware that freon may leak if the
dimple engages the pin which then engages the shrader valve. It
appears to be an insidious ever so slow leak. Different manufacturers
may have slight variations in pin length, dimple depth, etc. Even the
same manufacturer may have production variations. It isn't a function
of overtightening the cap either. The D's WAS finger tight. It's
finger looser now.

If it makes you feel any better, none of the Lincolns spit when I
loosened theirs.

Bill Robertson
#5939

>--- In dmcnews@xxxx, "jtrealtywebspannet" <jtrealty@xxxx> wrote:
> When converting to R-134 you are supposed to install new service 
> fittings so you can't use the 1/4 shrader fittings anymore. Generally 
> you remove the shrader valves in the 1/4 existing fittings and attach 
> a new adapter valve on top of it. If the dust caps have a dimple 
> inside that presses on the shrader valve then you are using the wrong 
> dust cap. The dust cap is not for sealing purposes, it is only to keep 
> the valve clean. They are supposed to be snug (finger tight). Most are 
> plastic and overtightening them will crack them. If you are still on 
> R-12 and someone replaced missing dust caps it is possible they are 
> wrong for this application. It is really easy when servicing A/C to 
> mix up dust caps for the Freon, the service valves, and service 
> gauges, etc. If this happens, to be safe, replace the caps or someone 
> someday may notice they are loose and tighten them up causing this 
> problem again. Leaving them loose they may fall off or at least let 
> dirt into the valve.
> David Teitelbaum
> vin 10757
> 
> --- In dmcnews@xxxx, "content22207" <brobertson@xxxx> wrote:
> > You learn something new every day...
> > 
> > Answering an eMail question for a fellow, put a gauge on my 
> DeLorean's
> > A/C. Quick connect adapter spit at me when I removed blue cap. And
> > I've lost freon. Appears cap was pressing slightly on shrader valve
> > all this time. Is possibile I mixed brands of adapters/blue caps. 
> Have
> > loosened on all my vehicles to be safe.
> > 
> > Just throwing into knowledge pool in case it'll help someone else...
> > 
> > Bill Robertson
> > #5939