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Re: R12 -> R134a 1989 Porsche Kit Questions

Posted: Sun Jul 16, 2017 4:53 pm
by Dougflas
HC3 wrote:Thanks Tim and Cusser,
It looks like HNBR O-rings come in black or green.
They may not be exactly the same (e.g. different durometer)
https://www.globaloring.com/oring-colors/

I guess I'll assume the QD fittings for R134a will be OK.
It makes sense after all this time at least the R134a fittings should have compatible O-rings.
I might try putting some teflon tape on the threads as a belt and suspenders approach.




When was the last time you saw Teflon tape on a vehicle AC fitting? I think you're making this a bigger deal than it really is.

Re: R12 -> R134a 1989 Porsche Kit Questions

Posted: Mon Jul 17, 2017 8:23 pm
by Cusser
HC3 wrote:I might try putting some teflon tape on the threads as a belt and suspenders approach.


Teflon tape is used to help seal tapered pipe threads. It won't help your O-ring connection to seal, but "might" help you unscrew the fitting in the future.

Re: R12 -> R134a 1989 Porsche Kit Questions

Posted: Tue Jul 18, 2017 6:19 am
by HC3
The teflon tape isn't near the O-ring just on the adapter threads. The idea is if R134a leaks past the O-ring it might be stopped by the teflon tape.
I'm well aware how the tape works on NPT threads.

Re: R12 -> R134a 1989 Porsche Kit Questions

Posted: Tue Jul 18, 2017 6:24 am
by Cusser
HC3 wrote:The teflon tape isn't near the O-ring just on the adapter threads. The idea is if R134a leaks past the O-ring it might be stopped by the teflon tape.


Better off buying lottery tickets.....

Re: R12 -> R134a 1989 Porsche Kit Questions

Posted: Tue Jul 18, 2017 5:50 pm
by HC3
Another annoying question.

Is there better Schrader valve and cap adapter assemblies out there I should get before doing the evac. and charge?
The Schrader valves look to be the standard type. The caps are plastic with a black O-ring or seal inside.
It seems that brass caps might be better. Thoughts? Thanks.

Re: R12 -> R134a 1989 Porsche Kit Questions

Posted: Tue Jul 18, 2017 7:51 pm
by Cusser
Why do those caps have holes drilled in them????

Re: R12 -> R134a 1989 Porsche Kit Questions

Posted: Tue Jul 18, 2017 8:10 pm
by HC3
They came that way - I had the same question.
I'll take a closer look to make sure the holes don't go thru.
I think those "holes" are to get a more constant wall thickness for the center part of the cap that has the male threads that thread into the top of the fitting.
It helps with the molding process.

Re: R12 -> R134a 1989 Porsche Kit Questions

Posted: Wed Jul 19, 2017 6:49 am
by HC3
Holes don't go through (thru) , it seems they are there for the reason I mention.
Still, should I look at finding better converters that have bigger Schrader valves and/or brass caps?
Thanks.

Re: R12 -> R134a 1989 Porsche Kit Questions

Posted: Wed Jul 19, 2017 7:17 am
by Dougflas
I have never seen brass caps for R134a either factory or replacement. You can get them for R12 systems thru HVAC supply stores.

Re: R12 -> R134a 1989 Porsche Kit Questions

Posted: Wed Jul 19, 2017 12:56 pm
by Cusser
HC3 wrote:Still, should I look at finding better converters that have bigger Schrader valves and/or brass caps?
Thanks.


No; you worry too much.