[Syntril]

Hello, I have a 2006 330i, and recently when I brake relatively hard my brakes make a slight screeching sound. I’ve already checked the brake fluid while the engine was cool, and the fluid looked pretty clean, as well as it was just under the max fill line. So at this point I assume that I just have to replace my brake pads.

Also related to my brakes, sometimes after I let go of my brake petal (usually on an incline i.e. my driveway) it doesn’t let go for like a second, and then it’s fine. There doesn’t seem to be any problems while actually driving, the brakes engage and disengage normally while driving (at least that’s what it feels like) so I don’t know if it’s just my car being weird or if my brake system is not functioning properly. The only other issue that I’m halfway conerned about is that there seems like there’s too much brake dust on my wheels. I’ll attach a picture to see what I’m talking about (those clean smudges are from where I took my finger and moved it across so it’s easy to see how caked on the brake dust is). I’m not sure if this just has to do with my brake pads being almost worn out but, if someone could inform me that would be great.

For the first issue, if it is brake pads could someone link me some decent brake pads that aren’t too cheap but also aren’t too pricey? Thanks.

[jsunma]

Welcome Syntri!l

A couple of things to your questions...

1) A "slight screeching sound" isn't really much of an indicator so far as needing to replace your brake pads. Nor would it necessarily be an indicator of low brake fluid (which you've already figured out is not an issue in your case). You don't give any info as to how long you've had this car and/or when this issue started. The best way to tell if you need new brake pads is to pull off the wheel and get a good look at the pads. Do they seem worn down to the base? Are they worn relatively evenly? If you're not clear on how to evaluate those things (that's fine! not everyone would know.) take the car to a trusted mechanic and have them check. Doesn't have to be a "BMW mechanic" as there's nothing exotic about stock E90 brakes. Likewise, you could trust your pad wear sensors (which if they exist and haven't been tampered with or broken). Those will trigger and you'll get a warning light (or iDrive message if you have iDrive)...then you know it's time to replace the pads.

2) You don't indicate if the delay in brake release is if you're facing down an incline or up. If this only happens when you're facing up an incline/hill, you've experienced the "hill hold" that your car should have. It's a feature, not a bug. See the manual for more info.

3) The brake dust in your picture is "normal" IMO for stock pads. If this bothers you, switch to ceramic pads (many here like Akebono) and you'll get much less dust.

Again, pardon if some of this you already know, but having a bit more info on your particular situation like how long you've had this car and your experience with E90 BMWs would help get you better answers. Good luck!!

[lookalikehuuh]

Everything Jsunma said, but adding in that I would recommend against "pad slapping" your braking system as that can become problematic and actually cause more noise.

A pad slap is when you swap the pads without changing out the rotor, or at least having the rotor machined. Nowadays the cost of machining a rotor is almost the same price as the rotor, so I would always recommend you swap the pads and the rotor at the same time.

You don't mention if your car the sport package or not, but that can change the pads/rotors you chose because sport package cars usually get a slightly larger caliper/rotor.

Anyway I personally own a 330i, and for some reason the calibration on that car's "hill assist" breaks are extremely sensitive so any incline will cause it to hold the brakes for me. I had the dealership look at the brakes like 10x and every time they said its operating normally. My 07 335i has far better calibration of the brake system IMHO.

I also recommend the Akebono pads are they are super quiet, and good stopping power, there is a slight "click' from the pads when you are changing direction of travel from reverse to forward but outside of that they are excellent pads. The Zimmerman rotors are coated and prevent rust pretty well. I have well over 100K miles on my set of Akebono/Zimmerman that I have on my 330i and they are still in great shape.
https://www.fcpeuro.com/products/bmw...34116854999kt2

[GoRomeo]

Gret answers. Check for stone pieces/debrie stuck in between the pads and rotors. While you there do a good pads/rotors cleaning.

I agree on those akebono pads. They are great. I have these in my e90. Love it no brake dust at all. Brembos not so much on my E88 🙄.

[Syntril]

Thank you all so much!! Sorry for not putting enough info in my initial post. I’m not sure if it’s the sport package or not.. is there a way to find out? I only got the car 5 months ago and I don’t know if this makes much of a difference but it’s manual, and I know that usually on manual cars you don’t have to replace the brake pads and rotors as often because of engine braking. Either way another detail I should’ve included is that it has 136k miles on it. And yes I was also talking about downhill so knowing that’s a feature is really great (I park my car on my driveway on an incline where the back two wheels are lower than the front two).

Thank you all for the info it really helps!!

[StradaRedlands]

Based on your style 162 wheels, you have a sports package. But run your VIN through RealOEM.com to find out for sure.

And I'm another satisfied Akebono customer!

[tcphoto]

BMW recommends replacing rotors and pads at the same time or at least have the rotors turned so you have a fresh surface. I went with the Zimmerman/Akebono kit from FCPEuro and am pleased with the performance and virtually eliminated brake dust.

[marvinstockman]

Why not pay someone to inspect your braking system, which will be a lot cheaper than the emergency room.

You also may have sticking calipers (extra dust) and a sticky emergency brake release.

[Efthreeoh]

Clarify, do you know the pads "are almost worn out", or just guessing/asking. Assuming the brakes were replaced once already (based on the car's total mileage) and the brake refurb was done correctly (meaning there a new pad wear sensor was used), the CBS (Condition Based Service) system should have an estimate of the remaining miles left for both the front and rear axles. If the pads are spent, there is a notification that appears in the gauge cluster between the speedometer and tachometer.

Screeching is a relative term. I have found women can hear brake noise better then men because women have better high frequency hearing then men do. All brakes make noise because there is friction between the brake pads and brake rotors.

As others have said, the brake hold function works both forward and backwards, but as soon as you accelerate the brakes release. The pad dust is normal for BMW original equipment brake pads.

Your brakes are operating normally. You should have them looked at however. It could be a pad has broken and the pad backing plate is contacting the rotor, or for some reason the wear sensor is not working correctly. It's very rare for either of those to happen.

[Syntril]

Originally Posted by Efthreeoh

Clarify, do you know the pads "are almost worn out", or just guessing/asking. Assuming the brakes were replaced once already (based on the car's total mileage) and the brake refurb was done correctly (meaning there a new pad wear sensor was used), the CBS (Condition Based Service) system should have an estimate of the remaining miles left for both the front and rear axles. If the pads are spent, there is a notification that appears in the gauge cluster between the speedometer and tachometer.

Screeching is a relative term. I have found women can hear brake noise better then men because women have better high frequency hearing then men do. All brakes make noise because there is friction between the brake pads and brake rotors.

As others have said, the brake hold function works both forward and backwards, but as soon as you accelerate the brakes release. The pad dust is normal for BMW original equipment brake pads.

Thank you for this reply. Yes, it’s not just a very tiny high pitched sound you can barely hear, it is an actual sound that I can hear as well as my friends can hear (though I do need the windows open to hear it), so I know it’s not awful because it’s not extremely loud, aswell as the actual condition of the brake disks looks pretty good aswell. Haven’t had the chance to take the wheels off and look at the brake pads yet, but. I’m a guy aswell, also my hearing kinda sucks lol so if I’m able to hear it I thought it was just a slight problem. But also yeah, there is no notification about the brakes on my dash, so maybe I’m just being paranoid. Could you explain how I can check the estimate on how many miles I have left on them through the CBS? I’m relatively new to BMW’s so I’m not fully sure how to access that data. I know how to access my oil level through the system, is it in the same area/way? Regardless, I now know what brake disks and pads I need to buy when I do need to change them so I’m thankful for everyone who commented.

[Efthreeoh]

Originally Posted by Syntril

Thank you for this reply. Yes, it’s not just a very tiny high pitched sound you can barely hear, it is an actual sound that I can hear as well as my friends can hear (though I do need the windows open to hear it), so I know it’s not awful because it’s not extremely loud, aswell as the actual condition of the brake disks looks pretty good aswell. Haven’t had the chance to take the wheels off and look at the brake pads yet, but. I’m a guy aswell, also my hearing kinda sucks lol so if I’m able to hear it I thought it was just a slight problem. But also yeah, there is no notification about the brakes on my dash, so maybe I’m just being paranoid. Could you explain how I can check the estimate on how many miles I have left on them through the CBS? I’m relatively new to BMW’s so I’m not fully sure how to access that data. I know how to access my oil level through the system, is it in the same area/way? Regardless, I now know what brake disks and pads I need to buy when I do need to change them so I’m thankful for everyone who commented.

Yes, the pad level is in the same CBS menu where you find the oil level. You have to be stationary with the engine on and toggle to you get to the "Service" menu. The press the slide swith to get into the service menu. Then toggle to the brake wear submenu. [Be careful not to reset the brake wear estimate, because that screws up the function].

The CBS will give you an amount in miles of remaining pad life. It is only an estimate. It's based on when the pads were last replaced and a new sensor installed, and the estimate is based on how the previous owner used the car, for example highway miles (low brake use) or city miles (high brake use). All you really need to do is pay attention to the brake wear indicator. It's the red "Brake" symbol (like when the hand brake (parking brake) is set, except there is no chime when the car is moving. The notification stays one when the car is being driven.

All that assumes the previous owner had the brakes refurbished in accordance with BMW specs and didn't cheap out and "tie off" the sensor.