After about run 6 of a 9 run autocross I ran yesterday after I particularly overcooked a corner, I noticed going back to grid that the brakes were making a loud squeak as I stopped (even from low pit-area speeds). I don't think performance is suffering at all as I went even faster my last three runs and won my class and finished 8th on PAX.
However, I'm doing the Toledo Match Tour next weekend. I was wondering if I should order a new set of pads to bring along or if this could just be normal performance brake squealing.
Note that the car is equipped with brake pad thickness sensors and they aren't indicating anything is wrong.
Visual inspection of one pad with the wheel on indicated adequate thickness.
Car is BMW 135i. Pads are OEM or OEM-style replacements (they were on the car when I bought it).
So what say the hive? are these pads on the way out or is it just a random sqeal that may actually not even be coming from the pad itself but the backing or slide?
On further inspection I've identified very small grooves on the front rotors. I've also researched the common causes of brake squealing and found that it almost always is not pad-to-rotor contact but pad backing within caliper movement/vibration. So I'm guessing the grooves are causing the vibration. I can try to bed the pads in again to try to smooth the rotor and eliminate some of the vibration, but it likely isn't causing me any performance issues. I also double checked pad thickness on all four corners and it is more than adequate. I think I could also re-grease the backing plate on the pads but I honestly don't have time to do that right now.
Sounds like you finally used your brakes a bit. Congrats!
I wish a squeeling brake pad was my only problem lol.
"Note that the car is equipped with brake pad thickness sensors and they aren't indicating anything is wrong."
My cars are far behind the times.. never knew this existed !
Would imagine its just time for pads.
chief8one wrote:
I wish a squeeling brake pad was my only problem lol.
"Note that the car is equipped with brake pad thickness sensors and they aren't indicating anything is wrong."
My cars are far behind the times.. never knew this existed !
Would imagine its just time for pads.
BMW has had brake pad sensors for over 30 years. I remember helping Dad replace one on my mom's '84 5 series.
In reply to boileralum:
My 79 Mercedes had them too.
To the OP: I would check to make sure nothing like a small stone is stuck in there, make sure everything looks ok and run them.
I would pull the pads and check for debris as bgkast suggested. Look for any signs of cracking on the pads and rotor. If it looks good, clean and reinstall and go hammer down at the match tour!
