My daughter's 2010 C30 cools the car just fine, but only for about ten minutes and then it blows warm air. She turns it off at that point and waits a few minutes before turning it back on. Once on, it works fine for another ten minutes. (It has nothing to do with acceleration.) Guys at Meinecke where she stopped in, told her it needed recharging. That didn't help at all - waste of money. They told her it must be the compressor for $2k. After reading other similar problems, I wonder if it has to do with a vacuum or sensor or relay. Had my local mechanic look at it and he replaced a relay but said it didn't help, so he thinks compressor. Any other ideas? How do you test for a vacuum leak? Thanks for any and all advice!

Unless my muffler was falling off while on a road trip, I would never go to a Meinecke shop or any other 'chain'. Have your daughter look for a Volvo shop in her area, it may cost just a bit more but at least the shop would be familiar with Volvo quirks. If she finds one she likes, get oil changes there and get to know the staff.

To test the clutch, I have used a stick to press the clutch in while the engine was running and the AC controls set to very cold. Beware of the spinning belt and other parts - see if you can easily insert a stick with the engine turned off first, the engine bay gets tighter every year. If the clutch engages (starts to spin) with very little pushing effort, the clutch needs to be shimmed.

The compressor only needs replacing if the bearings on the compressor go bad. When that happens, you will hear terrible noise when the clutch engages and tries to turn the compressor.

Shimming the clutch with zip ties does work. It is not "professional", but it is fast and cheap and should last a few years. The "professional" approach would involve taking off the clutch and moving the shims behind the clutch to get the correct gap, about 2-3 hours of work in a garage. No R134a is released in the process.
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Keeping it running is better than buying new

Read up on reshimming the AC clutch. The specific design of the clutch will determine where the shims go. Stick a screw driver in the hub of the clutch and give it a twist. You will discover the most likely place for shims. When you are done you may feel a slight drag but the clutch should be loose enough to easily turn by hand after it is shimmed up.

Greg

Thank you, Greg! Never heard of all this and I just printed some info from Matthews' site with shows the process in great detail. I'll see if my mechanic can figure it all out and save us a lot of money. :-) (This website is amazing - thank you, thank you!)