Brakes Grinding Intermittently

hyhoo0 · 10-01-2012, 03:32 PM

My front brakes are coming up be being due for service (about 2,900 miles indicated remaining), however the pads still look like they have some life left in them.

My problem is that I have started to get an intermittent grinding noise when breaking. It happens at least once on every drive but doesn't seem to be related to peddle pressure. The rotors definitely seem worn and I will probably replace them with the pads but there are no gouges or grooves on the surface that I would generally attribute to grinding a worn out pad into the rotor. The low pad sensor has also not been tripped.

My car is still under CPO. Should I get it checked out or does this sound at all normal and I should just replace the pads and rotors.

Any help would be appreciated.

ajm8127 · 10-01-2012, 04:03 PM

Over time a lip will form on the brake rotors because the pads do not contact the entire surface of the rotors. I had a lip on the inside and outside of each side of each rotor about 2 mm tall. One of my pads had less that 2mm of material left on it, so the lip made contact with the backing plate, causing a grinding noise. I replaced pads and rotors on the front axle.

You said you already checked the pad life. Are you certain you looked at all four pads? With only 2900 miles to go on these pads, I would have ordered new pads and rotors already. I bet changing them will solve your problem.

10-01-2012, 03:32 PM	#1
hyhoo0 New Member 0 Rep 19 Posts Drives: 2018 F80 M3 YMB 6MT Join Date: Apr 2009 Location: Vienna VA iTrader: (2)	Brakes Grinding Intermittently My front brakes are coming up be being due for service (about 2,900 miles indicated remaining), however the pads still look like they have some life left in them. My problem is that I have started to get an intermittent grinding noise when breaking. It happens at least once on every drive but doesn't seem to be related to peddle pressure. The rotors definitely seem worn and I will probably replace them with the pads but there are no gouges or grooves on the surface that I would generally attribute to grinding a worn out pad into the rotor. The low pad sensor has also not been tripped. My car is still under CPO. Should I get it checked out or does this sound at all normal and I should just replace the pads and rotors. Any help would be appreciated.
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10-01-2012, 04:03 PM	#2
ajm8127 Private 0 Rep 80 Posts Drives: '07 335i Join Date: Aug 2012 Location: Pittsburgh iTrader: (0)	Over time a lip will form on the brake rotors because the pads do not contact the entire surface of the rotors. I had a lip on the inside and outside of each side of each rotor about 2 mm tall. One of my pads had less that 2mm of material left on it, so the lip made contact with the backing plate, causing a grinding noise. I replaced pads and rotors on the front axle. You said you already checked the pad life. Are you certain you looked at all four pads? With only 2900 miles to go on these pads, I would have ordered new pads and rotors already. I bet changing them will solve your problem.
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