Ok, so the 709 and 508 are different.

The question I would pose is can the two be physically interchanged.
I know that either compressor would do the job.  The 508 does not have to be
used on a certain system.  They are used on many import cars, not just Vw's.

If the two are interchangeable, go get a 508 off any Golf, jetta or late
scirocco in the junkyard.  Change the head and your in business.

This is a good option at least for me, since my pull-it yard gets 30 bucks
for an ac compressor with 30 day warranty.  Assuming I could change and test
it in a month, that would be a substantial savings.

Of course this all hinges on the 709 and 508 being physically
interchangeable on the various vanagon motors(1.9, 2.1).

> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com]On Behalf
> Of The Bus Depot
> Sent: Wednesday, June 23, 1999 10:43 AM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: Is There Internal Difference between SD-508 and SD-709
> compressor?
>
>
> > I want to know if anyone knows for sure if there is any internal
> > differences between the two different Vanagon Air Conditioning
> compressors
> > (SD-508 for 83-85 Vanagons and SD-709 for '86 and newer)?  If
> they are the
> same
> > internally then the only real difference is the "head" of the unit (the
> back
> > end where the lines connect to the compressor) which can be
> swapped over.
>
>
> Unfortunately the different units used in the Vanagons (there are actually
> three altogether) are not interchangeable.  While Sanden does
> make a number
> of versions of each compressor, with different heads, they still are all
> called the same part number.  In other words, two SD709's with different
> heads (i.e. one used in a Vanagon versus one used on a Passat) would both
> still be called SD709's, but with a different suffix to designate the head
> used.  (Incidentally, for that reason, you may also want to take
> a look at a
> 508 that your supplier is offering before you sell one, if you haven't
> already, just to make sure the one they sell has the correct head for a
> Vanagon.)  The 709 is not just a 508 with a different head, it is an
> entirely different compressor.  Because there were several different
> compressors used, I usually ask my customers to provide me with a detailed
> description of how/where the hoses connect to the compressor (or have them
> read the complete Sanden number off of their old one) so I can
> make sure to
> send them the correct replacement.  If it's an '83.5-85 Vanagon, you're
> pretty safe because they all used SD508's (which I also sell).  But an '86
> could use any of three different compressors, and an '87-up one
> of two. Oh,
> and forget the microfiche; I have found it to be less than accurate about
> what years used what compressors.  Incidentally, the same holds true with
> receiver/dryers; VW used several different ones, and the
> microfiche does not
> accurately identify which Vanagons have which.
>
> - Ron Salmon
>   The Bus Depot, Inc.
>   http://www.busdepot.com
>   (215) 234-VWVW
>