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Old 06-20-2010, 08:46 PM
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partsetal partsetal is offline
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Default A/C conversion to R134a

I'm considering converting my 60 HT to 134a, and I'm aware of all the 'official' recommendations on how to do it correctly. My 'go to' Technician has done hundreds of conversions by simply draining/removing the old compressor oil and installing PAG oil that is for 134a, no other changes other than the service port adapters. Trouble is, the vehicles he has done were 80's vintage.
Has anyone converted their Squarebird to 134a? What changes did you make to the system? What results are you getting?
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Old 06-20-2010, 09:28 PM
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Default A/c

There some stuff out called envir o safe 12a, and you don't need to change the oil or anything, 6oz of it is = to 16oz of 134a or 6 oz = to 18oz r12. runs about $7-8 a can on ebay works great... learn about it from so nas car people.
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Old 06-21-2010, 02:03 AM
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simplyconnected simplyconnected is offline
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I am not an A/C expert, but the folks at Classic Auto Air are. They will help to prevent very expensive mistakes that most folks make.

I suggest you call them as they are the professionals for our old classic cars. They also guarantee their stuff.

This job may require changing your hoses to a teflon-lined type, which is more compatable with R134-a. Always use a new dryer, too.
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Old 06-21-2010, 10:24 AM
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DKheld DKheld is offline
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I'm really interested to see what happens - keep us up to date Carl. I'll probably go with R134 in mine (because of availability) but I am replacing all the hoses, drier, new aluminum condenser, and will be getting a rebuilt compressor with R134 seals. Here’s what I know from my conversions but as you mentioned they are later models.

Converted my '79 MGB to R134 7-8 years ago- worked good but not as cool at city speeds - great on the road - sold it so don't know if it's still working.

Converted my '87 Nissan truck using R134. Drained and flushed the system and compressor, replaced the drier, added PAG oil and R134. Cold on the road but almost no cooling in town. Got tired of that and tried Freeze 12. Supposed to be a direct replacement for R12. Drained and flushed the system, Flushed the PAG oil from the compressor. Added mineral oil back to the system. Worked great - very cold in town like R12 except...... at highway speeds the compressor will lock up then the belt will squeal - lucky the truck has an compressor on/off button so I just run it until I feel the load increasing then switch the compressor off. Did more research and found the Freeze 12 carries the mineral oil away from the compressor which is why it was locking up. Added some R134 and PAG oil. Now it's not as cold in town but doesn't lock up on the road as much. Figured it was not worth doing anything else to it until something breaks.

Like Dave mentioned - may be problems - I was told the molecules in R134 are smaller than R12 so hoses will probably leak but I didn't replace them on the MG or the truck. Also PAG oil which has to be used in R134 systems is supposedly corrosive to the old rubber hoses so they will eventually disintegrate as well as the rubber seals - thus the need for replacing the hoses and seals with the teflon style if doing a conversion.

My other '87 Nissan truck (brother bought it from me 3 years ago). Started leaking from a seal at the condenser when I had it. Took it to the dealer and told them to convert it to R134 - that was about (1994 ish). They told me they didn't have a kit to convert it. Service guy asked about it and I showed him the leak. They replaced the seal, oil and recharged it with R12 freon for approx $125 (again 1994 ish) - still works perfectly.

May be able to find a good shop that can still do R12 or a substitute that actually works.

Never got around to getting the certification to try autofrost (need the certification to buy it). Found out Freeze 12 is just R134 and HFC142b mixed. Be careful of the replacements - some of them have lots of propane and butane in them. On one site I just read R134 will be phased out in 2011 so who knows what we should use.

Good luck

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Last edited by DKheld : 06-21-2010 at 10:38 AM.
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Old 06-22-2010, 04:37 PM
RustyNCa RustyNCa is offline
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The 65 Special is rolling on R134a. So far so good. I don't know how the guy did it, but I am pretty sure he didn't change out any of the factory stuff(meaning lines, condensor, pump, etc.).

I remember him telling me with the early Fords and the monster compressor they seem to work fine with the conversion with little drama. Last drive we took her on, the A/C was to cold so we turned it down .
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Old 07-26-2010, 11:41 AM
Astrowing Astrowing is offline
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For those that have done the conversion to R134a, do you have updates to give an indication how its working over time? Somewhere I saw a conversion kit for the 58-60's that had all new hoses, drier, and compressor all for $589.
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