Converting from R12 to R134a

[DaviesKeymaster]

Has anyone recently tried to convert their AC system? I am in the midst of switching over my 1990 780 and have found it difficult to source certain tubes that have to come off of the receiver dryer. Volvo has limited retrofit parts available.

[GuillaumeParticipant]

Hi Davies,

You can find a conversion kit here:
http://www.skandix.de/en/spare-parts/interior-temperature/air-conditioner/dryer/conversion-kit-air-conditioner-r12-to-r134/1004292/

My US 780 was converted to R134a by the previous owner.

[dn010Participant]

I know you’re seeking the lines coming off the drier but for what it is worth – I am certain the drier can be cross referenced at your local parts house if you’re in the US. Here are some things to consider when converting to R134:

 

R134 molecules are smaller than R12, if your hoses are designed for R12 and are not upgraded, barrier hoses, the R134 will slowly leach through the rubber leaving you to top off the system on occasion. O-rings should also be replaced when converting.

 

Also you should at the very least replace the accumulator/drier and orifice tube. The system should be flushed to remove any contaminants and oil. Drain the compressor and refill it with Ester oil, as it is compatible with whatever trace mineral oil that may still be in the system.

[DaviesKeymaster]

I have completed the conversion. Flushed and cleaned the compressor, all new o-rings on the entire system (that took a while), new dryer and orifice tube. All is well but I now have a squealing noise coming from the orifice tube.  I used a variable design, which was recommended and am planning on doing an evac, replacing the orifice tube and then doing the recharge.  It runs great, super cold air,  but sounds like a dying animal at times!

[dn010Participant]

I know, stupid question – but did you make sure the variable orifice valve (VOV) was installed the correct direction? Was it missing the O-ring or loose when installed? I think VOVs are great but unfortunately they don’t always work for older applications. Some people get away with no issues, others rip them back out and put the orifice tube back in.

[errcl65Participant]

I was told to keep the R12 system and use R12 compatible (RedTek in Canada) DIY refridgerant.

[DaviesKeymaster]

The USA prices the R-12 very high and discourages the ongoing use of it for environmental reasons.  The R-134 is a lot less expensive to maintain once the conversion is done.

[DaviesKeymaster]

The USA prices the R-12 very high and discourages the ongoing use of it for environmental reasons.  The R-134 is a lot less expensive to maintain once the conversion is done.

[errcl65Participant]

RekTek is a compatible non-R12 refridgerant    http://www.redtek.com/win_12a_faq.html

The upside with R12 systems are they are less leaky then R134.   IIRC, the conversion kit is still

available from Volvo for aprox $150.    The A/C will be a separate project in itself,  gauge set and

a vacuum pump will be need off EBAY.   More tools 8)))).

Moto:  Buy the right tools,  learn to do it once and you can maintain a system for life.

[DaviesKeymaster]

Yes I just made the leap to the gauge set and vacuum pump -I had a hard time with replacing the in line orifice when I made the conversion, but finally got it working and the pressure right.

Keep us posted.

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