T85 a/c comp. change to diff. make?

[Ti Kan]

auditude at cox.net writes:
> Speaking of a/c, this summer it'll once again be hell here in AZ, so I need=
>  to get some plans in place.
>
> Has anyone here successfully swapped the York compressor for a completely d=
> ifferent type of compressor, like from a different car?  It seems to me it =
> would involve brackets, pulleys, and hose fittings.

Yes.

> I can weld up my own brackets, but need to figure out what type of compress=
> or would be easiest and best to use.  Is the stuff from the VW parts bin th=
> e same as the Audi stuff?
>
> I understand a good one to switch to would be a Sanden unit?  Is that a bra=
> nd name and/or a design?

Sanden is a brand name of compressors.  A popular unit is the Sanden
SD-5 series compressor (You can check http://www.sanden.com ).  It is
a lot quieter and more efficient than the York clunker.  There are
many variations of the SD-5 depending on whether you are going to
stay with R-12 or R-134a, and the style of clutch/pulley/fittings.

The basic mounting dimensions and bracketry needed for all SD-5 series
compressors are the same, and many refer to all of them as the "SD-508"
because that used to be the most commonly used unit by OEMs and hobbyists.
ICE (http://www.iceac.com ) makes a nice York to SD-508 adapter bracket
that you can use.  The SD-5 compressors come with the clutch and
pulley so as long as the bracket is mounted so that the pulleys line up
all will work, but you will need a different length belt than stock.

A brand new Sanden SD-5 compressor for R-134a runs about $200 street
price if you shop around a bit.  It comes pre-filled with the proper
PAG oil for R-134a systems.  If you go to R-134a you should completely
evacuate the system of old R-12 and oil, fix any leaks and either
use adapters for the fittings or have new R-134a barrier hoses fab'ed
for the compressor (the service ports for R-134a are different size than
those for R-12).  You should also replace the receiver/drier to one that
is R-134a compatible, and use R-134a compatible green nitrile o-rings.
Changing the expansion valve is probably a good idea too, but it's a
PITA to do on the type 81/85.

I did all this on my 4000 and the A/C now works great, much better
than it ever did.  The compressor I used was the SD-5H14 (model 4509)
which has a smaller pulley than the original York pulley, and that makes
the A/C work better at low RPMs.  This is fine with our cars because
even with the smaller pulley we can't over-rev the compressor (it has a
"redline" too).

> Do the compressor shafts come in different sizes?  I imagine one couldn't j=
> ust swap pulleys with some other compressor and line it up with the belt.  =
> I don't want to change the o.d. of the shaft or use a bushing or  anything =
> like that.

Don't need to worry about stuff like this with the Sanden.

> My friend commented that he believed the majority of compressors all spin t=
> he same direction, perhaps with the exception of Honda's because there's ta=
> lk elsewhere about their motors spinning the other way.  Is that true?

The Sanden spins the same way as the York, so you're fine there.

> I imagine besides all the fitment issues, as far as sizing is concerned it =
> just have to be from a car with a similar cabin volume, or what?

The SD-5 will work well as a replacement for any York application.
The compressor is smaller and lighter too.

> May as well switch to a compressor that is for an R134 car.  Do the low/hig=
> h pressure switched need to be changed to work with the different refrigera=
> nt?  What are the pitfalls for this?

No need to change the switches as those limits aren't changed.

-Ti
2003 A4 1.8T multitronic
2001 S4 biturbo 6-sp
1984 5000S turbo
1980 4000 2.0 5-sp
--
    ///  Ti Kan                Vorsprung durch Technik
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