Hi all,
I just observed that the A/C on our 1998 S70 GLT runs cool the first 30 minutes or so but blows less cooler air after that. I added the bread shims on the compressor clutch last summer and seemed to keep it consistently cool then. Any ideas?
Thanks!
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Brian M. - 1998 S70GLT, 1998 S70 GTA

You might also want to check the cabin filter if you have one. The air mixed needs to be close also.

Once things get hot, find a place to park and listen for the AC clutch engagement. The shims might have worn down after a year, they really take a pounding. Also, when cold, you might want to check the clutch gap, it should be around .020

I used thin aluminum strips rather than plastic for two reasons: consistent thickness for all 3 shims and the ability to fold it to the proper thickness.
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My back feels better when I sit in a Volvo seat

Hi Klaus,
I had the car parked yesterday and the clutch was engaged throughout the whole time (not cycling on and off) but the air blowing wasn't ice cold even at the lowest temp setting. Two things I forgot to mention was that (1) I topped off the A/C with refrigerant a month ago just to make sure, and (2) I replaced all 3 shims with new clips a few days ago.

Should I try to increase the thickness of the shims? Double the clips perhaps?

Thanks again!
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Brian M. - 1998 S70GLT, 1998 S70 GTA

So long as the clutch engages, the clips are good. Do not 'double' them up.

Is the engine fan running when the AC is on?

It is possible that you overfilled the system, sometimes too much will result in less cooling capacity. Check the pressure with the system running, it should not exceed 60psi. And, remember, the pressure goes up with higher temperature.
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My back feels better when I sit in a Volvo seat

You were right, Klaus. I finally decided to let our Volvo shop look at it and they said that when they evacuated the system they recovered 2.15 lbs (it should just be 1.61 lbs of freon).

So far the A/C seems to be blowing cold again!

Thanks!
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Brian M. - 1998 S70GLT, 1998 S70 GTA

The clutch may be worn out. I have a compressor (for sale) from a 96 that will work. Clutch is good and adjusted properly! (no plastic shims)
Tom