AC Compressor leaking refrigerant R134

PLEASE, can anyone tell me how to stop my a/c belt from chattering?? I have changed the belt and made it two inch's shorter,still chattering!!!!!!!!!!!!!!!!good info kstyer, maybe you can help me, gene

The belt chatters for several reasons.

First, it's too loose.  That alone will do it.  It's a long belt and tension is critical.

Next is contamination on the belt or pulleys.  If you have ever used belt dressing, you will need to clean all of the residue off of ALL the pulley grooves, and use a new belt.  You won't get that stuff off of the belt.   The dressing is an adhesive, and makes the belt stick to the pulleys, which can cause increased wear and chatter.  Dressing will also cause dirt and grit to stick to the belt and shorten it's life. It should NEVER be used.  Why do they sell it?  Someone will buy it.  Other contaminates can do the same thing.

Finally, the A/C is overcharged, creating too much stress on the belt.  This will also happen with the correct charge if the system pressure is too high due to lack of heat dissipation.  This is from restricted cooling fins in the condenser, or lack of air flow from many possible reasons.

Thanks guys, i had new (gates) belts put on this past week. (still chattering) I will have the other things checked as kstyer advised.

gene