GUNRU-GS4

I did my brakes yesterday, all new rotors and pads. I'm getting a loud scraping noise from my rear drivers side. I triple checked everything, cleaned every part, torqued every bolt to spec. I just went out and jacked the car tore off the wheel,caliper, and rotor to check everything out. The dust shield wasn't rubbing, parking brake seemed to be fine put it all back together and went for a ride, same thing. When I turn or go over bumps it starts. When I am going faster or apply brake it seems to go away. The Akebono pads are pretty thick and are right up against the rotor. So on the rear brakes there is nothing that pushes the pads away from the rotor when not braking?? The weird spring is suppose to hold them in place correct? I'm not getting any type of squeal its just a loud scraping sound. I did notice that one of the pistons of that caliper kinda came back out after I compressed it. Need some advice please.

AZDesertGS

iTrader: (4)

Did you do the "setting the pads" thing??? Go from 40mph to a stop, pretty firmly and do that 5 times. See if that helps. Im guessing the pads are just touching the rotor while you are driving (because it goes away when you lightly brake)

Just make sure the springs are all in place and the setting pin.

GUNRU-GS4

The Akebono ceramic pads say to take it easy for 400-500 miles, no bed in procedure. I just took caliper off and ripped everything apart, checked pistons, pads , spring and guide pin and everything looks good. I've done this 3 times today. The fronts and the other rear setup are quiet and all good. When I take a turn a little hard (still going slow on side streets) thats when the noise comes on the hardest. Doesn't really do it when I go straight. Once I straighten out and apply brakes lightly it goes away. I just had a friend ride in the backseat to confirm I'm not crazy and the noise is coming from the driver's side rear. I did not use a whole lot of grease on either side for the back of the pads. Just a thin coat and used the very thin stick on shims that came with the pads. I did the same on each side so that can't be it.

AZDesertGS

iTrader: (4)

Im pretty sure if you have everything back together OK then it has to be the brake shield. Mine did the same thing until I found that perfect small little bend where it never touched again. Mine did the scraping thing as well and it was the brake shield. Move it around a bit and then take a test ride and turn. Thats gotta be it.

GUNRU-GS4

I know this is nuts. Thats exactly what it sounds like. Brake shield rubbing. I'm gonna go bend it back a little. Maybe even though its not touching when I look at it, it does when the suspension flexes. My shocks are old. Here I go.

GUNRU-GS4

Man I just jacked up the car and removed wheel. The brake shield is not touching anywhere. NO scraps on shield or edges of rotor. When you guys replace rear pads do you use the Lexus shims or just what the aftermarket ones supply. I haven't messed with the parking brake but could that be making the noise. I don't ever really use it but I did engage it when I did my front brakes.

AZDesertGS

iTrader: (4)

Did you do the fronts as well???? Are you 100% positive its coming from the rear?? Sounds can be kinda tricky. Im still sticking with my brake shield theory.....just it may be the fronts

GUNRU-GS4

Alright well after tearing down my rear drivers side brake setup multiple times I found the loud scraping sound. I took the rotor off and checked the parking brake to make sure the shoes weren't rubbing on the inside of the rotor. I also check to make sure the brake shield wasn't rubbing even know thats what it sounded like. I checked this with the wheel off probably five times! Removed pads, spring, pin, checked pistons again everything.

This is what it was. See the shiny couple inches on the bottom of the metal lip that goes around the hub. Only in this spot for some reason it was rubbing on the inside of the little groove on the inside of the rotor. The rotor's groove goes over the metal lip and must be a pretty tight tolerance without touching.


I didn't notice the small area where it was rubbing because it was on the bottom. I finally took the rotor off for another inspectiona and saw this nice shiny groove on my rotor with some metal dust.


So I got out a little dremmel tool and ground the metal down a little bit on the bottom. Problem solved! I then looked at my old rusted rotor and it had been scraping to but it must have worn down so much I didn't really hear it. Finally I have nice smooth, quiet brakes.

AshburnM3

hows your parking brake shoes? they look pretty thin/worn from the pics

V8LexGS

LOL!!!

I did this same thing, and had to grind EACH SIDE with that exact tool THREE TIMES to get rid of that damnable sound.

It should be in the Lexus Owner's Manual that comes with the car.

"Prepare to buy an air grinder in the event that rear rotors need replacement."

tinman

A year later this thread comes in handy! thanks! I was having the same problem, fixed using the same method.

Boostless

iTrader: (12)

wow, just did rear brakes yesterday and had this same problem!

GS4_Fiend

iTrader: (22)

Nice find! I figure it would be the splash guard thats grinding against the rotor.

YviE

iTrader: (3)

Does this happen with different brands of brake rotors? I'm putting on new rotors and discs tonight and am worried I'll have the same problem. I got OE equivalent rotors.

tinman

It was happening with the stock rotors on my GS300. It also happened with NAPA brand rotors and AutoZone rotors (which i think are Duralast?). Seems to not be related to the brand of rotor.