v2gucci68

My car : 2015 Lexus RCF at 32000 miles

Job : recently replaced both rear brake pad (Project MU NS 400) and rotors (Centric Premium OE type) and sensor (Power Stop)

Issue : high pitch scratching noise from rear brakes (not grinding noise) , noise at both cold/hot time

Attempt : (1) already been driving 700 miles after replaced new pads/rotors , (2) already did 7 times 70mph-15mph bedding process , (3) mechanic said it’s due to Project MU is aggressive racing pads and needs longer bedding time with new rotors , so just keep driving it normally until rotor surface becomes satin/matt finish.

My question : (1) Anyone experience this ? (2) How to fix it ? (3) What other aftermarket pads/rotor would you recommend ?

Opinions, comments welcome.

Thanks for your input.

05RollaXRS

I have had it since I got my RCF and it is totally normal for high friction pads that have very high stopping power especially under repeated heavy use. Your mechanic is correct. Once mine warm up, the noise goes away.

Porsche even made a video about it

kukudm

How bad is it? I guess the rear pads are hard to bed in, as they get less use than the front pads.

v2gucci68

Ok got it , thanks so much ....

v2gucci68

chirping noise is kind of loud at 10~30mph that you can hear it with windows shut, barely hear it +40mph. So it's very embarrising when pull in/out of parking lot.

Mingofish

You sure the clips are installed correctly?

v2gucci68

not sure , mechanic said he's sure install was done correctly , maybe i need to go to another shop to find out , thanks for the input...

lobuxracer

iTrader: (2)

The springs in the rear calipers can move out of position and rub against the rotor pretty easily. I discovered this on the first rear pad change on the wife's GS F. Like you I initially thought it was the pads not bedding correctly, but after a few good heat cycles, I knew it had to be something else. It was the centering spring. It shifted out of position on the right side rear and was scraping the edge of the rotor. Popped in back in place and now I make sure they're positioned correctly after installing the wheel before driving. Almost as bad and bending the dust shield and having it rub against the rotor.