anybody know what his part is and what it does?

i've been hearing a ratcheting sound from the front disc brakes when i step on the brakes at low speed recently. today i decided to open the front brakes to see whats up and this thing was found under the dust cover. looks like it could have been causing the ratcheting sound, just by the shape of it. i've fixed front disc brake car for years, but never encountered this part.
any ideas? do i need to keep it? is it an original part that usually gets tossed?
inquiring mind would like to know

 

Yeah, that brass piece is factory. Joe explained that too me, but I'm not finding the thread. Not sure if my memory is correct, but I think it had to do with grounding to prevent static in the radio. If I'm totally off base someone will speak up with the correct information! John

 

You got it. It's a static dissipator. I guess either Olds figured out it didn't do much or else newer radios were less sensitive, because they eventually stopped using them.

 

No kidding. I never heard of such a thing. Wow.

 

thats interesting. learned something new today. thanks for the info, guess i won't throw out those parts now.

 

Is that rotor grooved really bad or is it just the camera making it look like it is?

 

Uh...no, that rotor is not grooved bad. That's the way they looked when they left GM. Well...between the static deals and rotors, I'd say Scotty442 has a REALLY low mile car. How many miles on that thing Scott?

 

That groove was the wear indicator. When the groove was gone, it was time to replace the rotors.

 

Thank you oldspackrat! I have never seen that before, but it makes perfect sense.