Nobody Knows A/C?
 

I have an 04 Silverado with the 4.3.
Rear of ac compressor is spitting freon on top of the drivers side valve cover.
appears to be coming out of a little valve pointing at the valve cover.
only spits out when compressor kicks off, does not cool.
Should i go to the shop for a new compressor or is there a valve or switch i can replace myself?

thanks very much.
ron