bmwlexus09

Just replaced both front & rear pads with oem pads. Turned both front & rear rotors too. Now there’s a whirly grinding noise coming from rear of vehicle when braking. Checked rotors, clips, shims, caliber, and everything checks out. Even lube guide pins. Still makes a whirly grinding noise when braking. Any thoughts on what’s causing the whirly noise?

afpj

Don't know your skill level, so bear with me. You sure it's the rears? Sounds can be hard to pinpoint solo. Have someone outside the car confirm? When you say check everything, you took all apart again, pads went back on correctly, one of those spring wire pieces that hold the pads didn't pop off?

bmwlexus09

I’ve checked the rotors, pads, clips and made sure no springs fell off or came loose. I was reading that some ceramic pads might produce a grinding noise when new. What are Lexus oem pads made of?

salimshah

Brake job includes a spin and brake test of each wheel. You can lift each wheel and spin it and see if you hear the noise. You can then ask an assistant to gently apply brake and the parking brake (for the rear) one at a time. With the wheel on, it may make it easier to test.

Salim

RX in NC

Did you properly bed in the new brakes after you finished installing them?

bmwlexus09

I did do spin test and I can hear a bit of scraping as the wheel turns. Does that indicate the rear rotors are warped? These are original rear rotors and first time that these were turned. I did attempt to bed the new pads and rotors but didn’t go over 30 mph before braking. It was a medium length parking lot so couldn’t build much speed. Could that also have impact? Thanks for all your suggestions.

RX in NC

I would go out on an open empty road and bed those brakes in hard. First things first.

salimshah

All wheels, or one wheel? If rear, is from the parking brake.
As our friend use to say, "use your earballs" to zero in to the source of noise.
Typical scraping is from a bent shield or max adjusted rear brake.
Warped rotors would give pulsations during normal braking..
Deposit on disc surface should have been scraped off during turning.
Once mounted, the disc has a slight wobble [bearing run out] which should push back the pistons in couple of rotations of the wheel. If your brake fluid is dirty/old it can fight and not flow back, and may take a longer time for the pads to move away.
You can get sticky pads if you did not clean the two surfaces of the disc and sharp braking can help burn it off.

Salim