New brake pads this past summer... Very noticable groove etched into wheel side of rear brake rotor and sounds very bad at low speed....Any suggestions...?

 

With a noticeable groove, it may be time to replace the rotor. I replaced my fronts at 40K miles or so because they'd reached their min. thickness as engraved in the rotors and had noticeable groove. My rear didn't need replacement at the time because I use the rear brake very little.

As for the noise, not sure if the wear on the rotor is the cause or not, but with an older bike and groove, I'd check the min. thickness on the rotor.

Carl

 

Thanks for the info... rotor has 24,xxx mi. on it....