Date:         Thu, 19 Jun 2008 00:03:24 -0700
Reply-To:     Keith Hughes <keithahughes@QWEST.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Keith Hughes <keithahughes@QWEST.NET>
Subject:      Re: AC High Side - line leak - rubber hose
In-Reply-To:  <20080619035142.E86735D1408@mpls-mf-01.inet.qwest.net>
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> Date:    Wed, 18 Jun 2008 22:06:14 -0400
> From:    "Jack R." <jack007@COMCAST.NET>
> Subject: Re: AC High Side - line leak - rubber hose
>
> Roger,
>
> I have a 4 year old, new compressor, a new condenser, have already changed
> all the 0-rings.  I have the professional gages, and my system held a vacuum
> when last charged, before my engine swap.  The system is currently empty,
> due to the excessive leak in the High side hose, so when I swap the hose, I
> can put my vacuum (thanks to Harbor Freight $17) on the system to pull all
> the air and moisture out.  I will change the dryer too, before the recharge.
>
And, of course, before you evacuate the system.
> I do have about 6 or 7 cans of R12 on my shelf, but intend to swap to R134a,
> and save the R12 for my 91 Mazda Miata (which uses 1/2 can a year).
>
> I have done AC work before, and will attempt this one.  With 134a, in an R12
> conversion, I've been told to keep it at about 80% capacity, due to the
> higher efficiency of 134a, with a smaller condenser.
R134A is, in no way, *more* efficient.  It is much less effective than
R-12, and you really need more condenser area (or much higher condenser
efficiency) to make it work decently (depending on where you live of
course).  You use less volume due to the greater expansion, and thus
higher head pressures, with R-134A versus R-12.  If you have a pre-1987
Westy, with the split condenser, I wouldn't convert if I were you.  You
won't be happy with the results (using the stock condenser), because
these systems are lame with R-12, much less R-134A. BTDT.  'Course it
was 112°F here today, so YMMV.  Since you're remaking one hose already,
you might also check out Arizona Mobile Air (www.azkits.com) and replace
your condenser with a more efficient parallel flow style.  Just have to
modify one additional hose.  About $100 for a condenser (and I have no
affiliation with them), plus another hose end.  You really ought to
flush the system as well, to get all the mineral oil out.  Good luck.

Keith Hughes
'86 Westy Tiico (Marvin)