My 1994 850 turbo has 190K with the original compressor. It was switched to 134A about 10 years ago. When the air conditioning no longer cooled I evacuated with vacuum pump and refilled. It works for 3-4 days. I have added the leak sealer and the fluorescent dye. I have not found the source of the leak. It just takesa small amount of refill to get it working again. I also have noticed that it will stop blowing cold on hot days after about 30 minutes of driving. Is it possible that an overheating/pressure switch is malfunctioning and/or blowing off freon? What should I try next?
Thanks.

 

Hi,

Most likely the evaporatour is leaking R134a. While the evaporatour itself is not that expensive, the labour can add up quite a bit (close to or over $1,000), as much of the dash components have to come out just to get to the evaporatour.

Check out the 2 posts:
https://volvoforums.com/m_7364/tm.htm
https://volvoforums.com/m_34431/tm.htm

And one post from a 3rd party:
http://volvospeed.com/Repair/ac.php

I hope this gets you started.


JPN

 

Compressor Clutch gap is bad the most likely cause if it bloes cold for a little while then stops.

If you can next time it stops check for power to the compressor with a test light.

If you have power and the compressor isn't on the compressor clutch needs to be reshimmed.