Johnmowog@aol.com wrote:
> Re: the R134 discussion...
>
> Having had a couple of cars including an XJ6 converted I can offer the
> following .02 worth... Yes, a good flush out and change of fittings is a
>start, but
> for longevity sake changing hoses is recommended as they are permeable
>enough
> that R12 and oil residue wll stay in the system forever. (Also, hose leaks
> are the 90th+ percentile cause of AC failure anyway!) A new evaporator is
>useful
> as well, R134 models tend towards larger than original to try to overcome the
> lack of efficiancy. An upgrade in the size of the accumulator valve which
> controls flow (I'm no expert but I think that's what the guy said it did...)
>made
> a very noticable difference. None of these parts were expensive, a couple
> hundred bucks and a couple hours labor and he was done.
Not accumulator valve, but expansion valve. If the system is equipped with one,
a larger flow is recommended (note that
some older systems--GM, for example--used a graded orifice tube, rather than a
valve).
I'm glad someone finally mentioned hoses--this is one of the items which ought
to be changed in any conversion to
minimize leakage, if there is any suggestion that the R-12 hoses aren't up to
it. The molecular size of R-134a is
smaller, and will therefore pass right through some hoses that worked just fine
with R-12 or R-22. Any hose which uses a
Teflon liner will leak (we used braided stainless/teflon liner hoses to plumb
the A/C on buses first specified for
R-134a, just as we always did with R-22, and the first ones off the line leaked
out eighteen pounds of R-134a in two days).
Cheers.
--
Michael D. Porter
Roswell, NM
[mailto:mporter@zianet.com]
Never let anyone drive you crazy when you know it's within walking distance.
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