Date: Mon, 28 Jun 1999 13:09:59 -0700
Reply-To: Randy Bergum <organslave@EARTHLINK.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Randy Bergum <organslave@EARTHLINK.NET>
Subject: Re: AC Part II
Content-Type: multipart/alternative;
Hi John:
Ice and freezing usually mean there is a restriction somewhere - at
least that's what they taught us in A/C school. Check the expansion valve
by rapping a screwdriver on it to see if it's stuck or clogged. Also check
that both coils are clean.
I once had a 1986 GTI that had an A/C problem, and there was a little
chunk of metal that had lodged in the expansion valve (a small block of
aluminum with passages machined into it). The dealer put a new one in and
charged me big bucks, but the old part was usable by removing the top cap
and pulling that bit out - you have to remove the freon first......
I recently yanked out the screen in front of the rear evaporator coil
and cleaned the coil with picks, brushes and coil blaster spray. A
fantastic drop in temperature! The screen doesn't appear to be easily
removeable, and that is poor design.
Also, you can check the level of charge in the system by the sight glass
- it will show bubbles and froth when undercharged. At that point in the
loop, the working fluid should be all liquid, so connect your freon to the
low side, adding VAPOR (can upright) until the bubbles go away. You should
gently heat the freon container because the liquid requires heat to
vaporize, to replace the vapor going into the system.
Moral: Learn as much as possible about your system, then you can
troubleshoot and save money. Get an EPA license, too, and stay legal.
Randy Bergum
1990 Vanagon
John Dorn wrote:
> Hi there,
>
> A few days ago I asked about my evaporator freezing, wondering if it was
> the switch with the capillary tube that is inserted into it. I got some
> different suggestions so today I spent a little time with it. I checked
> the evaporator fins to make sure they were clear (they were for the most
> part but I cleaned them a little more), then ran the ac while right next
> to the evaporator. Almost instantly a bit of moisture formed on half of
> it. This continued to form until the moisture slowly began turning to
> ice. I could hear the switch right there cycling on and off but it is
> located in the half of the evaporator that was not icing. I took a
> quick drive and I could tell that the switch was cycling on and off when
> off things would begin to melt, when on they would freeze up again
> (freezing a little bit more area each time), all the while the section
> of the evaporator where the capillary tube goes in never even developed
> moisture.
>
> Any guesses?
>
> Oh, I also gave a quick visual inspection of the rest of the AC
> components while it was running, everything looked normal except for the
> receiver/drier site glass where the color was orange (is this my
> problem?).
>
> Thanks for your help
> John
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