Re: [Chrysler300]

You will need an evaporator regardless of the compressor. There is no reason to expect that the compressor has failed just because the evaporator has. I would repair/replace the evaporator and go for it.

However, if the compressor is oily around the clutch or manifold fittings things change. As I said I have not found a source for the compressor gaskets and some of them have a steel core. Some of the compressor rebuilders have an R134 conversion kit with a modern Sanden compressor. The change requires flushing out all of the mineral oil used with R12 because it may gel when in contact with R134. PAG oil is required with R134. If you stay with the original compressor there are compatible refrigerants such as R414a and R416a. R12 is still available but expensive.

On Thu, Jul 2, 2020 at 11:55 AM John Nowosacki <jsnowosacki@xxxxxxxxx> wrote:

So, what is the recommendation for cool, reliable A/C in a 57 300C that came from the factory so equipped? I have a leak (unfortunately in my evaporator- hear hissing from cowl vent under pressure). Do I go through the work to take out the evaporator and have it repaired, only to hassle with the possibility that I won't be able to make use of the original compressor? Do I just hang an underdash unit in the car and run new lines to the existing compressor and see if it will hold vacuum and then refill and hope for the best? Has anyone come up with an adapter mount for a more modern Sanden style compressor that will work in the same mounting configuration as the original? It would be great to have the original system working, even if less efficiently by converting to R134, than to have nothing at all except the 'look' of all the factory components in place.

On Thu, Jul 2, 2020 at 11:45 AM Marshall Larson granitledge@xxxxxxxxx [Chrysler300] <Chrysler300-noreply@xxxxxxxxxxxxxxx> wrote:

Marshall Larson
10:43 AM (1 minute ago)
to Robert
The original compressor on your car was the 55-60 version which is different. The major difference is the two piece front bearing housing with its own carbon seal that is apparently not available and likely wouldn't work in the later compressors. The current seal may work in the first gen compressors but I haven't put it to the test yet.

Another major difference are the heads and valve plates which are not individually interchangeable between versions of compressors. Perhaps late version head and valve plate pairs will work on early compressors but I haven't tried that. Gasket sets for the early compressors are not available and those I have seen listed for the late version are no longer available. I would like to know how the rebuilders solved this issue.

Another difference is that all early versions had an oil pressure regulator that seems to have been eliminated at some time in the later version. Even that regulator had been changed during the early version production run.

I have not seen any early version compressors pictured in the ads for rebuilt compressors. The difference is obvious at the front of the compressor. It is possible no one will ever see the early version as a rebuilt.

Any corrections and added information to this post is welcome. Particularly regarding gaskets.
--

--
Marshall Larson