Brakes squeaking while not braking

[cobra]

I replaced my brakes with new Zimmerman rotors and Textar (OEM) pads from FCP. Since then, I have put a couple thousand miles on them and I have this annoying squeaking coming from them while doing low speed (10-15mph). While braking they are quiet.

I took them apart and greased the contact points and put some "disk brake quiet" on the back of the pads even though they already have shims on them stock. It made zero difference and they still make noise.

The one weird thing I noticed is that the front pads don't really stay clipped into the piston, they tend to tip out of the piston.

Any idea what to try next?

[Estoril]

Well - something isn't right in the re-assembly. Make sure that the piston-clipped pad is squarely/fully inserted, and square to the rotor. The outside pad needs to sit with it's 'ears' properly into the slots. The ears should not bind. I assume you inspected the slider pins and they are clean, abrasion-free and fully tightened. It goes without saying that the bracket needs to be fully secured and the rotor locator bolts clean, problem free and snug.

Is the rotor face showing odd marks? If so, pic pls.

[cobra]

Well - something isn't right in the re-assembly. Make sure that the piston-clipped pad is squarely/fully inserted, and square to the rotor. The outside pad needs to sit with it's 'ears' properly into the slots. The ears should not bind. I assume you inspected the slider pins and they are clean, abrasion-free and fully tightened. It goes without saying that the bracket needs to be fully secured and the rotor locator bolts clean, problem free and snug.

Is the rotor face showing odd marks? If so, pic pls.

So, I was having the squeaking and decided to do full caliper rebuilds with new seals, boots, guides, etc. Zero change to the squeaking noise.

I will inspect the inner rotor face but the outer looks normal.

[eacmen]

Did you touch the rears as well? Make sure dust shield isn't touching. You would be surprised how a tiny bit of contact can cause.

Also could be a rock stuck in between pad and rotor. Try driving in reverse really hard in a parking lot and it might dislodge it.

[PSUEng]

Some compounds don't do well in the cold regarding squeal. My TRD pads on my GX are like that. Has the outside temp dropped?

[cobra]

It's been like this all year round. No rocks or anything since I just had these completely apart

[Slideways]

Bedding-in again is really the only thing that might quiet them down. While these Textar pads have good bite and mild dust, they make this light groaning noise when slowly coming to a stop (last few inches) and then again when braking in reverse. Nature of this pad compound, I guess.

[cobra]

Like I said, if I am actually braking they are silent. It's only when I'm not braking. I can make it go away by lightly pressing the brakes so they just make contact with the rotor.

I feel like the pad popping out of the caliper piston might be the culprit, because it's probably tipping out and buzzing. This is the 2nd set of Textars that do it. Must be a defective pad spring.

[Bry5on]

Stock brakes? I have a super loud humming noise in my 996 brake setup with … textar pads. Pretty sure mine is a different root cause, but textar is the common denominator here. Noise disappears the moment I touch the brake pedal.

[cobra]

Stock brakes? I have a super loud humming noise in my 996 brake setup with … textar pads. Pretty sure mine is a different root cause, but textar is the common denominator here. Noise disappears the moment I touch the brake pedal.

Yeah stock brakes. Damnit Textar!

[Slideways]

Like I said, if I am actually braking they are silent. It's only when I'm not braking. I can make it go away by lightly pressing the brakes so they just make contact with the rotor.

I feel like the pad popping out of the caliper piston might be the culprit, because it's probably tipping out and buzzing. This is the 2nd set of Textars that do it. Must be a defective pad spring.

Is the noise from the front pads or the rears?

Yeah, can those pad tangs be bent outward to clamp better to the piston? Other than that, maybe the outside anti-rattle clips lose their tension and need to be replaced every so often.

[cobra]

I believe it's from the front pads. I recall trying to bend the tabs but they are very stiff springy steel that didn't bend very easily. I can certainly give it another shot.

[bmwfnatic]

I would like to add that my daily (non-M E46) has this same problem, making noise while NOT braking, the second I apply even the slightest pressure on the pedal it goes silent.

I try not to spend too much time on that car because A) it’s far from perfect and B) I have so many other projects…

But I have completely disassembled the brakes and checked and re-greased them, without finding or solving the issue, it doesn’t really bother me that much, since I need the windows down to hear it, but it’s stupid nonetheless.

The common denominator though, is that car is also using Textar pads and rotors…

I hope you figure it out.

[sapote]

The one weird thing I noticed is that the front pads don't really stay clipped into the piston, they tend to tip out of the piston.

There is no gap between rotot - pad - piston, so how does the pad tips out from the piston with the clip "bites" in the piston bore? Can you pull the clips wider so it locks harder in the piston bore?

[cobra]

There is no gap between rotot - pad - piston, so how does the pad tips out from the piston with the clip "bites" in the piston bore? Can you pull the clips wider so it locks harder in the piston bore?

Yeah I will try this. The clips don't bite into the piston and actually want to push themselves out of the bore.