Lost the cool over time in my red vanagon. The AC system was gone
completely through early last fall, with all new seals,vacuum and
pressure checks, new compressor, expansion valve, dryer, etc. Gave it
the whole nine yards. Worked great until recently. In this summer heat I
have been running the system hard, and have slowly lost the cool. So - I
have been studying Youtube videos to learn about AC, and get examples on
how to self service. Have learned a lot. One video in particular caught
my attention and that was regarding the Shraeder valves used in the high
and low pressure service ports. I have learned that 80% of the leaking
of refrigerant from the AC systems is from the Shrader valves. The
remaining 20% is of course from other points in the systems. But this
makes the case for checking the Shraeder valve as the first items on the
maintenance checklist. Of course that can be done the same way one might
check a propane tank - light a match, right? Of course I jest here - but
using soapy water on the valve same a for a propane tank will show any
leak at the Shraeder. If one has a leak, it raises the question: How
does one change out the Shraeder valve without loosing the refrigerant?
Well, turns out there is a little tool specially designed to do the job.
Works slick as a whistle. Here is a link to a Youtube video showing a
Shraeder valve change out using that little tool.

http://www.youtube.com/watch?v=Cfm6m01FfeI&feature=endscreen&NR=1

The videos on Youtube about AC systems and servicing are well worth
watching. Takes the mystery out of AC.

Regards,

John Rodgers