Date: Fri, 30 Sep 2016 15:38:17 -0500
Reply-To: John Rodgers <jrodgers113@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: John Rodgers <jrodgers113@GMAIL.COM>
Subject: Re: '91 Carat AC - again!
In-Reply-To: <1556146619.2232582.1475251951066@mail.yahoo.com>
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I have done some more thinking on this, and now have more questions.
When the trinary switch failed, the AC system was not running. In fact, it
had never run while in my posession, even though I had serviced it to get
the compressor to run . I had it flushed, then put on a new receiver
dryer, added a 134a conversion kit, pulled a vacuum check, and then put in
PAG 46 (I think that is the number recommended, and one can of
refrigerant. The compressor should have turned om. It did not. I checked
the clutch, and it did not engage. I jumpered it and it worked fine. Also
turned the compressor by hand with clutch engaged. Compressor turned fine.
I assume an electrical problem. And never turned the system on again. For
whatever reason, the shrader valve under the trinary switch failed,
allowing the refrigerant to blow out, which in turn also blew out the
switch. Replacing the shraeder valve with another supposed good one from a
134a converstion kit was not sufficient. It blew out as well, causing the
loss of refrigerant again.
There was only the pressure of one can of refrigerant present, and the
system had not yet been run. So this shraeder valve failure really puzzles
me. As I see it, there was not enough pressure there to cause a failure, if
the valve seals were good.
The fact of a failed trinary switch may have created the illusion of a
failed shraeder valve. The switch could have failed pressing on the valve
much like a thermostat will hot instead of cold. I am thinking of removing
the trinary switch again, replacing the shraeder valve and just leaving the
trinary switch off until it is recharged with one can of refrigerant. If it
holds, then I will install my new switch, and see if that holds. I'll turn
the system on, and if the compressor kicks on(it should - it did on my
'88 model), then I will finish recharging the system.
I know a blockage somewhere could cause a problem, but the flush was done
with receiver/drier removed, and the crud wash out of the hoses in all both
directions intil it was clear. The condenser section was done separately
from the evaporator section. I was right there when this was done, so I'm
fairly certain the system is clean.
In preparing to do this again, if anyone feels I've missed something, I
would appreciate hearing about it. Around here locally there's only one
guy to talk to about this and his is a system he built, so its very much
not VW, and the nearest shop is over in the big city.
Any comments would sure be appreciated.
Regards,
John
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