There's a 3/16 allen wrench plug on the snout (atleast i think its a 3/16) pull it off and the fluid should be pretty dang close if not at the bottom of the threads from the plug. Otherwise thats the only fluid in the charger. Easiest method if u think its the s/c is to pull the supercharger belt off and run it and see if the sound goes away. If it does its prolly s/c coupler and zzp sells a really good one