random brake grinding noise?

[HubertGummer]

rear disc, e brake appears to be the same pads.

At least I cant find a replacement pad specific to that system, and I didnt see a separate pad. when I had the wheels off.

Usually with rear disc brakes the Ebrake is a mini drum system on the inside of the rotor. Commonly called a "drum in hat". You have to remove the pads and rotor to get to the ebrake shoes.