blackz151

I recently did pads and rotors on my 07 z51. Ebc rotors with carbotech pads from ampd.(great company btw). Now I any time I apply the brakes anything past 15-20% I get a thumping knocking noice that slows down as the car slows down. I can not seem to pin point if its a certain wheel.

Does any one have any idea what the cause for this may be or were I can start looking. There is no vibration or kick back in the pedal its just a very annoying noise.

Adam@Amp'dAutosport.com

Are the rotors slotted?

1hander

sounds like the rotor is hitting something , is there any chance one of the rotors had a defect on the surface...

since it slows with speed...its definitely rotation related....take it apart and see of there are any defects on the rotors.... i would think that with a thumping like that you might be able to see where two things are making contact.

any chance that theres some debris or something sitting under one of the rotors..

1hander

i didnt even think of that.... the drilled rotors on my 540i are quiet under normal braking..but if i really clamp down on them i get like droning from the holes in the rotors.

blackz151

They are. I know ebc said they will make a little noise because of the wider slots but I though this was excessive and wanted to make sure there wasnt anything majorly wrong

Boomer111

Over torque the rotor bolts? Warped rotor. Easily done.

But with no pedal vibration maybe not.

blackz151

Thanks! yea that was what I was thinking. I get no vibration at all. The car is solid when I get on the brakes it just makes noise.

timd38

Did you replace the sliding caliper bolts and boots? They can bind up and cause issues.

blackz151

I did not replace them I did grease them. I was thinking about replacing all the boots and shims that the pads slide in.

1hander

slotted rotors FTW