LOW-speed (under 10mph) Brake squeal

Old 02-28-2011, 06:21 PM
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woojoo83
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LOW-speed (under 10mph) Brake squeal

Folks, i'd like to solicit all of your expertise and experience. And before someone asks the obligatory question, my answer is "yes", i have utilized the search function and did not see anything along the same vein as my issue here (https://www.myg37.com/forums/tsb-tec...eak-noise.html).

So, my 2009 G37S 6mt coupe has a braking squeal that sounds off ONLY UNDER 10mph (-ish). That is, if i start driving, do not exceed 10mph, and then proceed to brake to a stop, my brakes emit a pretty shrill, clear, squeal/screech, whatever you want to call it. It does this for forward and reverse, doesn't matter.

Strange thing is, is that if i drive and exceed 10mph(-ish), and then proceed to brake to a stop, there is no sound whatsoever. Quiet as a mouse (as it should be!).

I had my 30k service done about two months ago and the mechanic noted there was plenty of the pads left.

Any insight? Thanks in advance.
Old 02-28-2011, 10:03 PM
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soolman32
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It s pretty common occurrence for BBK. I think it s particulary pronounce with our cars due to the composite of the break pads that come from the factory.
Old 03-01-2011, 12:27 AM
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xyz
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I was told by the dealer that this is due to brake dust build up . . .
Old 03-01-2011, 12:46 AM
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fairladyz34
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Ive found the brakes to squeal when go slow right after start up on both my 370z and g37. Seems to be common and is just noise from initial bite?
Old 03-01-2011, 01:12 PM
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ualdep
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Hi, I had the same problem, so I go 11 mph THEN stop; JK; My dealer rpl pads & rotors;

no problems; I suspect glazing on the pads or rotors uneven due to hard braking; maybe

dealer can remove pad glazing?

09 G37S Sedan 9K
Old 03-01-2011, 04:53 PM
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woojoo83
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Originally Posted by soolman32
It s pretty common occurrence for BBK. I think it s particulary pronounce with our cars due to the composite of the break pads that come from the factory.
Soolman32, what is "BBK"? Is the manufacturer of our brake pads? Is that an aftermarket manufacturer? My G is bone-stock with the exception of tint.

Originally Posted by xyz
I was told by the dealer that this is due to brake dust build up . . .
XYZ, wouldn't brake dust be cleansed off during routine car washes, rainstorms, etc?

Originally Posted by ualdep
Hi, I had the same problem, so I go 11 mph THEN stop; JK; My dealer rpl pads & rotors;

no problems; I suspect glazing on the pads or rotors uneven due to hard braking; maybe

dealer can remove pad glazing?

09 G37S Sedan 9K

Ualdep, thanks for the info about the dealership replacing your pads and rotors, however, doesn't that fall under "normal wear and tear" of the vehicle? Regardless, what/how did you explain to your dealership in such a way that resulted in them replacing your pads and rotors?
Old 03-02-2011, 10:17 AM
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ualdep
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Hi, my car was still under 1st yr warranty. The rotors got rpl too because I had an earlier problem with brake shudder.


09 G37S 9K
Old 03-04-2011, 12:59 AM
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xyz
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Originally Posted by woojoo83
Soolman32, what is "BBK"? Is the manufacturer of our brake pads? Is that an aftermarket manufacturer? My G is bone-stock with the exception of tint.



XYZ, wouldn't brake dust be cleansed off during routine car washes, rainstorms, etc?

By "BBK", he meant the "big brake kit" that comes on the Sport.

Yea, that is what the dealer said. I did not get the car wash at the dealer, so the dealer say they usually power spray down the wheels during the wash to fix this issue.
Old 03-04-2011, 01:16 AM
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chuckie311
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my old car did the same thing and it was worse in the winter..
Old 03-04-2011, 01:22 AM
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P Casey
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its common for our cars, have dealership clean brake dust off once a month. aslo if you use any tire wet or dressing this could have an effect.
Old 03-04-2011, 01:37 AM
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JEBperformance
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why does brake makes noise

One we all agree is brake squeal are annoying. Calls unwanted attention from passenger, other motorists, and especially you the drive.

However they are just like herpes. Once you got them symptoms can be treated but will never go away. They are combination of factors and can not be pinpointed to a single issue.

High pitch sound is produced by high frequency vibration between your rotors and your brake pads. Just like musical instrument, when conditions get right they start making noise at precise moment.

If your pads are good stated by your dealer, there is nothing to worry.

However if the noise gets worse or you feel vibrations on your pedal. Than you should worry.

Try following and if the noise still persists go to your dealer. Resurfacing of your rotors are covered under warranty.

Bed-In Properly
Try break clean, they are very cheap and easy to use
Lubricate the calipers
Old 03-04-2011, 07:19 PM
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APRacing-ChrisB
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OP: This is typical for brake pads this size and shape at low speeds and light brake pedal effort. BMW, Mercedes, Evo, STI, etc., customers have been dealing with the occasional light-effort brake squeal for years.

What often happens is the pad transfer layer (the slightly darker area on the rotor surface) can eventually rub off with light use. This is why people who drive more aggressively don't experience this type of squeal as much as those who drive more conservatively. When then transfer layer wears thin, the pad relies only on abrasive friction as adherent friction is no longer available. Abrasive friction tends to excite the harmonic frequencies in the pad / rotor / caliper / upright / hub / bearing / wheel / tire assembly more than adherent friction tends to, leading to high frequency feedback (brake squeal). You may notice that if the pedal effort is increased, the noise often stops. This happens because pad and rotor vibration is effectively damped by the additional force exerted by the heavier load.

My suggestion? Well, without being there to provide a full evaluation, I would normally recommend re-bedding the pads. This will refresh the pad transfer layer and get the brakes back into the adherent friction realm. It usually works, but not 100% of the time. I would also suggest flushing the pad/caliper with water before re-bedding to loosen up any brake dust that is trapped between the pad back plate and the pad abutment surfaces on the caliper.
Old 03-04-2011, 10:58 PM
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JEBperformance
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Just make sure brake rotors and pads are fully cooled before putting any moisture. Especially brake clean, they are colder than water.
Old 03-04-2011, 11:00 PM
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LizardBreath
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good advice in this thread
Old 03-05-2011, 01:46 PM
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J2S2M
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Originally Posted by JEBperformance
One we all agree is brake squeal are annoying. Calls unwanted attention from passenger, other motorists, and especially you the drive.

However they are just like herpes. Once you got them symptoms can be treated but will never go away. They are combination of factors and can not be pinpointed to a single issue.

High pitch sound is produced by high frequency vibration between your rotors and your brake pads. Just like musical instrument, when conditions get right they start making noise at precise moment.

If your pads are good stated by your dealer, there is nothing to worry.

However if the noise gets worse or you feel vibrations on your pedal. Than you should worry.

Try following and if the noise still persists go to your dealer. Resurfacing of your rotors are covered under warranty.

Bed-In Properly
Try break clean, they are very cheap and easy to use
Lubricate the calipers
I wish more vendors were like you guys. You guys actually contribute to this forum. Not just trying to sell products and milk us for our $$$. Keep it up guys!

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