[Vwdiesel] a/c compressor body failed (fwd)

[Gary Bangs]

\\Hijack on
Yes R-134 hoses are specificsally designed for the smaller R-134
molecule as compared to the R-12. However, older R-12 hoses are
successfully used because the pores in the rubber are filled in with
micro-debris over the years of use, sealing them and the hose for use
with R-134.

That's what I've read. I'm just the messenger!

-Gary


> 
> Forwarded message:
>> Thanks.  Do you have any suggestions on where to get the O-ring kits?  I
>> have a friend at a local mechanics which is where I get many of my
>> parts.  However, their supplier has boxes of o-rings rather than a kit
>> for doing a single car.
>>
>> Have you heard of R12 hoses being leaky in an R134 system as the poster
>> below suggests?  Given the price of hoses, I'd rather not replace them all.
>>
>> I'm also not clear on the solvent step.  Is the idea to run that through
>> each of the pieces or through the whole system in some way?
>>
>> Thanks,
>> Scott
>>
>> Val Christian wrote:
>>> I've probably done 14 or 15 R-12 to R134a conversions.  
>>>
>>> The o-ring kits are under $20, and for some conversions I've been able to 
>>> buy all the R134a compatable o-rings for $3.  
>>>
>>> A dryer is relatively inexpensive and helps get any extra R-12 oil out
>>> of the system.  Normally when I service an AC, I've replaced the dryer,
>>> figuring that it's cheap insurance.  There are times when I haven't, 
>>> however, and they are times when there is a fresh dryer on the system.
>>> When that is the case, I draw down the system for the better part of the 
>>> day...drawing it down, and then sealing it off, and then drawing it down
>>> again a couple times over 12 hours, or let it sit over night.  This
>>> effectively helps boil off any moisture.
>>>
>>> Finally, I have one of those bottles, which can hold flush solvent,
>>> under pressure, with a rubberized tip.  A gallon of flush is cheap
>>> and does 4 or 5 cars (or 3 minivans with rear AC).  Again it helps
>>> clear out old oil, and particulates from older or failed compressors.
>>>
>>> Spending the incremental money on these steps has resulted in never 
>>> having a failure with a r134a conversion.  
>>>
>>> I have friends who have cut corners, for example not swapping out the
>>> o-rings, and then had problems two seasons later.  For the money and
>>> time invested in maintaining an AC system, I'd rather have the results 
>>> be trouble free.
>>>
>>> Val
>>>
>>> ps: I have an evac pump now, but an old regrigerator (r22) compressor
>>> works OK, just takes a little more time.  But they are inexpensive.
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>> Scott,
>>>>
>>>> If you do decide to go ahead with an R12 to R134a conversion, be advised 
>>>> that R134 tends to leak through hoses that otherwise will hold R12.  It 
>>>> has to do with the smaller molecules in the refrigerant.
>>>>
>>>> Also, residual mineral oil lubricant from R12 in the system can cause 
>>>> major problems because it doesn't mix with the PAG oil used with R134, 
>>>> therefore the plumbing system has to be thoroughly cleaned.
>>>>
>>>> See what I went through converting the A/C to R134 in my '81 RabbitTruck 
>>>> at the following web address:  
>>>>
>>>> http://chemdec.natsci.csulb.edu/VWAC
>>>>
>>>>
>>>> -- 
>>>> Bob Soukup
>>>> '81 RabbitTruck D.
>>>>
>>>>
>>>> On Wed, 26 Dec 2007 22:18:02 -0500 Scott Alexander 
>>>> <salex at dsl.cis.upenn.edu Wrote:
>>>>> One of the mounting ears on my A/C compressor on my '82 Rabbit D failed.
>>>>>  The compressor seemed to be working fine up until I discovered the
>>>>> problem.  I'm wondering if anyone has experience  swapping the guts from
>>>>> a working compressor into the body of a failed compressor?  How hard
>>>>> would it be to do this?
>>>>>
>>>>> Assuming it's not a fool's errand, does anyone have a seized or
>>>>> otherwise failed compressor sitting in the junk box that they'd like to
>>>>> get rid of?
>>>>>
>>>>> Since I'll have to crack the system to fix this in any case, I'm also
>>>>> thinking of switching to R134.  I know I'll need to replace the
>>>>> receiver/ dryer and various seals.  Is there anything else I should know
>>>>> about this swap?  Anything peculiar to Rabbits that the guys I know who
>>>>> have done this on other cars wouldn't expect?
>>>>>
>>>>> Thanks,
>>>>> Scott Alexander
>>>>> '82 Rabbit D
>>>>> Warren, NJ
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>   
>>>> _______________________________________________
>>>> Vwdiesel mailing list
>>>> Vwdiesel at vwfans.com
>>>> http://www.audifans.com/mailman/listinfo/vwdiesel
>>>>
>>> _______________________________________________
>>> Vwdiesel mailing list
>>> Vwdiesel at vwfans.com
>>> http://www.audifans.com/mailman/listinfo/vwdiesel
> 
> _______________________________________________
> Vwdiesel mailing list
> Vwdiesel at vwfans.com
> http://www.audifans.com/mailman/listinfo/vwdiesel
>