Hi,
I'm new to the forum (only been reading for some time) and need your help please. Four months ago I bought a used 2008 135i with 30,000km/19,000 miles and the car needed new brakes. I only use the car on the street (just a little spirited).
So I decided to buy new Cool Carbon pads S/T (due to forum recommendations I read about their performance/low noise/low dust) along with new genuine BMW performance rotors (drilled and slotted). This was around a month ago, so it's been already around 800km/500 miles after installation.
The first week or two after installation I did not get any noise or grinding, but around 2 weeks and 350km/200 miles later I’ve started noticing break squeal more and more often and louder. Also sometimes when coming to a stop with the brakes hard on the pedal I can feel and hear like some kind of grinding on the front of the car. I don't think the ABS is activating because no lights are flashing? The grinding cannot be felt on the steering wheel, there’s no vibration or pulling to either side (wheel bearings and alignment are fine). I can also hear a hum when braking hard (I think this is due to the drilled and slotted rotors right? It's my first time with these kind).
What could the problem be for the squeal and grinding? I have already done numerous bedding procedures following Cool Carbon's recommendations on their website (repeated hard stops and letting the brakes cool). All brake components are correctly lubricated and installed, so my mechanic is very confused and can’t find the problem? He has disassembled the calipers and pads with me watching and applied lube/grease twice and everything seems to be fine and correctly installed. I even tried disconnecting the brake sensors but the squeal was still present.
My mechanic has now recommended to once again change to new pads but this time go with original BMW pads because he is blaming the Cool Carbon pad material causing the squeal.
Besides the noise and grinding the stopping performance doesn’t seem to be affected and seems very good.
Do you have any ideas what could be causing this or other things to check to finally fix this?
I have already read many threads similar to mine but can't find a specific fix and don't know what else to try besides new pads.
I really appreciate your help before spending more money oonce again on new pads, thanks!