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Discussion Starter · #1 ·
I’ve finally had enough of my a/c compressor clutch being worn out and am going to fix it instead of just bandaid-ing it with bread bag ties. When the car is first started and the clutch still works it blows pretty cold but I don’t know how cold/efficient a fresh system is. I don’t mind buying the tool to do it myself but I see kits on ebay that include the compressor, drier, oil, & a new switch for ~$150, which is less than an oem clutch. I can also get a friend to evacuate and recharge the system. The dilemma I’m having is which way to go. Multi-piece kit from fleabay or just what is failing? Car has 133,xxx miles. If anyone has performed similar work with similar mileage, was there a marked difference before/after from maybe slight freon loss over the years or other inefficiencies over time? Any and all opinions welcome
 

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From what I understand,your clutch just needs re-shimming. There may already be 2 or 3 shims and you would just need to remove one. Mine only had one shim and the gap was too small if I removed it. So, I bought the kit of shims (don't recall the price but fairly cheap). I was able to borrow the A/C clutch tool from Auto Zone for free. Advance Autoparts and others have this deal too. The car had over 150K miles and there was no need to recharge the system.
 

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Discussion Starter · #3 ·
Just removing shims? I thought they wore out, for whatever reason, and measuring/ compensating for the increased gap was a temporary fix?
 

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Just removing shims? I thought they wore out, for whatever reason, and measuring/ compensating for the increased gap was a temporary fix?
TBH it is the official Volvo procedure in Vida, I think even the compressor is designed for that very thing, exactly why shims are there.
Did that recently on mine, 2 shims removed, works like a charm since.
 

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Discussion Starter · #5 ·
Huh, interesting. Ok, another silly question then. How many shims get stacked up behind the pulley? I know it will vary, that’s how shims work, but will some have only 1 and some have 5? Or is it a little more consistent than that?
 

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I just did this job, and had two shims, one thick and one paper thin. I had to take them both out to get the gap to spec with my feeler gauge. I think when you run out of shims to remove, and still have too wide a gap, that's the end of the clutch.

Also, the Y-shaped AC clutch tool was only like $12 on Amazon, so if there's any fee at all to rent/borrow one you may as well just buy it. It worked fine to pull the clutch face using the M6 bolt and fender washer trick in the center and tightening the M5 bolts around the outside.
 

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The D,
The shims are not what wear. They provide the cap for the electro-magnetic A/C clutch. As the clutch wears, the gap gets gets wider. Eventually the gap get too wide for the electro-magnet to engage the clutch. When the clutch is cool, the electro-magnet has more strength as its coils have lower resistance. Also, while the clutch is cool, the gap may be narrower. As the clutch heats up, it becomes weaker due the resistance of the coils increasing (normal) and the gap widening due to thermal expansion. Combined, the electro-magnet does not have enough strength to engage the clutch. This explains why the A/C may work for about 5-10 minutes then stops working.

By removing shims (or replacing with thinner), you restore the original specified clutch gap and it should all work nice again.
 

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IIRC, there are 3 shims in Vida's datagram, but cant say if its just generic drawing or every compressor would have the same.
It is going to vary from compressor to compressor. When they are made, what ever thickness and quantity of shims are used in order to achieve the specified gap. Mine had 2 shims but if I removed one the gap was too narrow. I had to get the shim kit that has several shims of various thicknesses. I was able to get the kit from FCP Euro but they had to special order it.
 

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Discussion Starter · #12 ·
The D,
The shims are not what wear. They provide the cap for the electro-magnetic A/C clutch. As the clutch wears, the gap gets gets wider. Eventually the gap get too wide for the electro-magnet to engage the clutch. When the clutch is cool, the electro-magnet has more strength as its coils have lower resistance. Also, while the clutch is cool, the gap may be narrower. As the clutch heats up, it becomes weaker due the resistance of the coils increasing (normal) and the gap widening due to thermal expansion. Combined, the electro-magnet does not have enough strength to engage the clutch. This explains why the A/C may work for about 5-10 minutes then stops working.

By removing shims (or replacing with thinner), you restore the original specified clutch gap and it should all work nice again.
Yes, I understand this. How bad does the wear between the clutch faces get? If I remove shims and get the gap correct will it be fine for another 100k? Or will the wear just keep accelerating and I’ll have to repeat this in a year or so? I may be back to square one and buying a clutch and pulling tool
 

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Yes, I understand this. How bad does the wear between the clutch faces get? If I remove shims and get the gap correct will it be fine for another 100k? Or will the wear just keep accelerating and I’ll have to repeat this in a year or so? I may be back to square one and buying a clutch and pulling tool
That I believe will vary based on how close to spec you can get the gap but I would think that it will last a long time. I would also think that the most wear of the clutch would occur early in life. My first V50 went about 180K miles before it needed to be re-shimmed, mileage will vary. I think that if you keep the car long enough and if it ever needs to be re-shimmed again, you will find that it is pretty easy to redo once you know how.
 

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Discussion Starter · #14 ·
Yay, I fix it!

Finally had an opportunity to fix my a/c problem. It took a bit longer than I thought it would, but I’m also used to working on cars on a lift and not in my driveway. I only had two shims behind the clutch and removed the thicker of the two. Thanks everyone for the advice
 

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Cool! ... literally
 
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