Air Conditioning Noise

Yesterday I added a can of R134A to my truck due to the 95* weather :doh:. Anyway, whenever I first turn it on, (max a/c setting) it makes a grinding/slipping noise. It only does it 2 or 3 times and then it stops. I also noticed the noise once during the winter when using the defrost. Is there any common problems or things I should look at? Once the air is on it works fine though in all of the settings. The truck also has a new serpentine belt if it matters. Thanks guys!

Check your A/C clutch air gap. Sounds like you have some wear, that or your bearing is going out.

How would I go about doing that? I have no knowledge about this stuff. I had a thought about it being the bearing too.

Feeler gauge to check the gap.. you should able to do a quick search, I can't remember the gap setting.