Squeaky brake pedal? Not pads/rotors

[IVM3]

My brake pedal is squeaking, and it's most noticeable when letting off the brakes. This has nothing to do with the pads or rotors as the noise is coming from the pedal assembly. Has anyone had this issue and fixed it somehow?

I tried lubricating as much as I could and it hasn't helped. This isn't my video but it's exactly the same sound (found this from the F30 forum). Any help would be great!

[FlyingLow78]

I've had this exact issue on another car before and it was caused by the master cylinder. The dealer tried changing the fluid first per the regional tech rep, but it didn't help, so they replaced the master cylinder under warranty and all has been well since.

[Jamongkad]

Damn I'm having the same sound! So it must be the master cylinder?

[IVM3]

Originally Posted by Jamongkad

Damn I'm having the same sound! So it must be the master cylinder?

I meant to reply to thank FlyingLow78. Upon taking a very close look, there was a tiny leak of brake fluid too. Replacing the master cylinder fixed the issue. If you're not under warranty, expect to pay a little over 1k including labor. The part itself is nearly $500.

[Jamongkad]

Originally Posted by IVM3

I meant to reply to thank FlyingLow78. Upon taking a very close look, there was a tiny leak of brake fluid too. Replacing the master cylinder fixed the issue. If you're not under warranty, expect to pay a little over 1k including labor. The part itself is nearly $500.

Holy moly okay! I might have to ask around from different indy shops then. My car's warranty has expired.

[Jamongkad]

Originally Posted by IVM3

I meant to reply to thank FlyingLow78. Upon taking a very close look, there was a tiny leak of brake fluid too. Replacing the master cylinder fixed the issue. If you're not under warranty, expect to pay a little over 1k including labor. The part itself is nearly $500.

Question though is this a sign of a failing master cylinder? I don't notice any degradation in brake performance.

[IVM3]

Originally Posted by Jamongkad

Question though is this a sign of a failing master cylinder? I don't notice any degradation in brake performance.

Yes it is a sign of a failing master cylinder. I noticed no difference in brake performance either. I would get it fixed as a precaution because it's certainly not worth risking your brakes over this.

[Jamongkad]

Originally Posted by IVM3

Yes it is a sign of a failing master cylinder. I noticed no difference in brake performance either. I would get it fixed as a precaution because it's certainly not worth risking your brakes over this.

Ok thanks! Still a little pissed though since I only have 28,000 miles on my M3. It's concerning that the master cylinder will be failing after such low miles.

[Jamongkad]

Just to chime in. It was a faulty brake master cylinder. Had it replaced with a new one and the sound went away.

[IVM3]

It turns out my squeaky master cylinder was due to using ATE Typ 200 brake fluid. I would avoid that fluid. Details here:

https://f80.bimmerpost.com/forums/sh....php?t=1843543