I am getting the issue of the a/c compressor cutting out after 10 minutes at highway rpms. I have read that it is likely the magnetic force of the clutch losing its grip due to the heat and centrifugal force. I intend on doing the "bread twist" shim fix( http://volvospeed.com/vs_forum/index.php/topic/80181-850-ac-clutch-gap-fix ), but my compressor looks quite a bit different than the 850 model in the write up, and I wondered if anyone has successfully done this fix to their 2004'ish model? Also, how does the plastic cover for the freon port come off? I put a socket on it and it just turns? I also couldnt pop it off?? I figure I should check the pressure at least in the system before trying to mess with shimming the compressor.

I just shimmed my compressor. It works!! The compressor still cycles properly and it was quite easy, after I used a pair of pliers to shove the shim in place.

Your compressor is different and will require a metal shim, glued into place. I would use metal that is .020-.025 in thickness. You can use a feeler gauge to check the gap between the clutch and compressor.

Klaus
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Always willing to listen, just not able to take direction.

Same symptoms on my 2002 XC70: AC ran 15 minutes in hot weather (TX) before failing. Turning off for awhile, and then trying again gave me a few more minutes. Highway driving allowed it to stay on longer, but I got very little time in stop and go traffic.

A $1000 estimate spurred me to try a shim. A little challenging to get past the frame, but with help pushing in the clutch from the top, I was able to slip one metal shim in from the bottom. I started with only one and it worked.

An $0.89 fix!

It sounds more likely that the system is freezing up on you rather than the clutch being too loose. It's not that hot in NY these days.

As to the plastic dust cover on the port, it is only supposed to be finger tight. It does have threads, so I suggest using your fingers to turn and pull upwards at the same time.

Klaus
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Always willing to listen, just not able to take direction.

I did do the check when the compressor kicked off with the a/c on high where I nudged the clutch with a broomstick and it immediately slapped back onto the compressor and spun. Would this indicate it being the clutch, or could it be freezing up? Also it seems that the compressor will stay engaged at lower rpms around town, but it cuts out at highway rpms?

Instead of bread clips, use metal. See reply #7 in the thread below, which I didn't copy here because of the picture.

http://volvospeed.com/vs_forum/topic/80181-850-ac-clutch-gap-fix/

Check the clutch gap first so you know how thich the metal is supposed to be. I would also put in the 3 clips, re-measure the gap, and then glue the clips into place.

Let us know how this works out,

Klaus
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Always willing to listen, just not able to take direction.