You will need to replace the drier, all the R-12 oil in the compressor,
and flush the system of any oil residue. Then you will need the proper
amount of HC-134 (it will take the same amount as 12). Lastly you will need
to change the service port fittings. Any Flaps will have everything you need
in a kit. Btw this kit will include you need, plus a decal stating its been
changed over to 134. The price of the kit will vary, but $50.00 to $75.00
should cover it. If your handy you can DIY, you will need to vacuum the
system down before charging, so if you don't have a pump, take it to a shop
and have it vacuumed.
    We have been doing this job on all makes for years now with good luck.
Some cars cool better then others. Has to do with the size of the condenser,
amount of air flow, and evaporator. All the Vanagons we've done worked
great!
    If you have any questions just yell.

Howard

>> Well I have been given an ultimatum by the wife. Get the a/c fixed or get
>> rid of the Vanagon. Its about to hit 100 degrees here in AZ so it would
>> be nice to have working a/c again. The system was working fine around 10
>> years ago but lasted maybe one year after a $450 refill with freon at the
>> VW dealer. It's still the freon (R12) system and I'm not prepared to pay
>> the cost of regular R12 refills so it has to be a conversion to R134.
>> How much should it cost to have this done? I was quoted a $1000 flat fee
>> by one place but that seems expensive. Is a lot of labor involved? Can a
>> regular a/c place handle this or is the Vanagon system too unusual?
>>
>> -David (1987 Wolfsburg)