brakes squeling

[bruce12861]

I have about 19k miles and I noticed the brakes are squeling bad when going slow. I have an appt next week for service, multiple issues but the main on is service indicaztor for brake fluid service.

I have seen a few comments about brakes squeling due to brake pad sensors being "?faulty" or poor design .

Does any one have a service bulliten so I can sohow it to muy dealer?

[bruce12861]

[marc.scroggins]

[marc.scroggins]

I had this problem and the dealer initially tried to insist that it was normal for these brakes and was caused by brake dust. It sounded like metal grinding so I brought it in anyway and had them look at it.

They found something loose within the brake mechanism and either tightened it or replaced it (can't remember). No issues since it was fixed.

[Kilovolt]

There is a very high probability that this is caused by the brake pad wear sensors on the outer surface of the pad material, I had this at 15k miles and it has now returned at circa 21k miles.

UK dealer found the issue (after a few hours messing about) which is a squealing noise most commonly heard at low braking forces as the car slows to a halt (you can’t hear it anywhere near as much at speed, if at all).

You’re not going to’ believe the explanation.

It turns out that the pad wear sensor is made of a harder material that the pad material itself (doh!), as the pads are wearing down the sensor becomes proud of the pad surface (like a small probe sticking out) and that gives rise to the squealing?

I said you would not believe me :-)

The resolve was to remove the pads and quickly grind the pad sensor lower than the pad surface. This does not cure the problem but it stops the squeal coming back for several thousand miles.

UK Dealer told me that ‘Germany’ are working on a new generation of pads/pad sensors and this should be fixed the next time the car has new pads fitted (no talk of changing them out under warranty though).

The squeal has just started to return to mine (exact same noise) and it is due for service over next couple of months (depending on mileage of course) so I will get them ground back again (or new pads fitted as car is service inclusive for 5 years so not my cost either way).

Of course your noise may be different, but there’s a very good chance this is the same issue for you.

I bet Cobradav can find a service bulletin for this – now there’s a challenge.

Trust this helps a bit. Luck.
English spec Titanium Silver Coupe, Auto Gears, Dynamic Drive (Sports Pack in USA?), Adaptive Steering, Adaptive Headlights, Sat Nav Professional, Comms Pack With Business Phone, Lights Package, Folding Mirrors, 120 Style Alloys, Tints, Service Inclusive 5 Years/60,000 Miles.

[Mark in SBA]

Actually, you were fed a line by the service guy. The pad wear sensor is made of a plastic button with a wire embedded. As the pad wears, the disc grinds it's way thru the sensor and grounds the wire.



Trust me, the plastic sensor is not harder than the brake pad. Squeaking brakes are caused by vibration, and cured by either a strategically located rubber pad on the back of the pads or liberal use of brake grease (BMW speak: "Plastilube") on all the sliding stuff.



Just have them grease up the pad backs and calipers a bit.

[AndrewDP]

there was so much confusion at my dealership when I tried to order tyre pressure sensors for my May build 650i sport optioned conv? I ordered BMW Radial Spoke 118 wheels and Dunlop runflat tyres and was told all kinds of things (like the stems were tthree different colors and it depended upon which color mine are - silver)before they finally ordered the tyre pressure sensors. Of course, I had given them the VIN for the car, but they kept telling me that BMW uses different/no sensors on the same models. At first they told me that I did not need any, but I persisted. I just hope that my $340 buys me the correct stems and sensors for my winter wheels. Hard to believe that in Boston in mid-October they do not know more about winter set-ups and the need for sensors on the car.

[vetracer]

[vetracer]

On this one you are not correct. the sensor you have shown and are
talking about is on earlier model BMW'S.
All the newer version cars have a different sensor setup.
The sensor is in constant contact with the rotor and has a resistor
in it. The more it wears and thinner it gets changes the resistance to the computer so it can calculate the miles left on the brakes.
The squealing is caused by the material used in the early versions of
these new sensors and the fix is to replace the sensors with updated
ones, and per BMW SIB the pads get changed as well.

[cobradav]

Sorry I missed this one earlier.

SI B34 02 06
Brakes March 2006
Technical Service

This Service Information bulletin supersedes Service Measure B34 202 03 dated July 2003.

SUBJECT
Brake Squeals

MODEL
E60 (5 Series)
E61 (5 Series Sports Wagon)
E63 (6 Series Coupe)
E64 (6 Series Convertible)

SITUATION
Some customers may complain of a brake squeal noise during light brake application.

CAUSE
Wear sensor geometry (part of the sensor head protrudes beyond the edge of the brake disc).

Wear sensor material (the material combination of the wear sensor/brake disc can cause squealing noises under certain circumstances).

CORRECTION
In case of a customer complaint, install improved brake pad wear sensor. Improved wear sensor geometry and material have been implemented in 01/06.

PROCEDURE

Determine that the noise is not caused by random occurrence which can happen just before the brake pad wear limit is reached.

Replace the brake pad wear sensor and new brake pads only on the noisy axle.

PARTS INFORMATION
Part Number..............Description.................. Quantity

34 35 6 776 421.... Wear Sensor, Front E60/E61/E63/E64...1

34 35 6 776 422.... Wear Sensor, Rear E60/E63/E64....... 1

34 35 6 776 423.... Wear Sensor, Rear E61............... 1

WARRANTY INFORMATION
For information only.
_______
US '05 645 Coupe, Silver Grey, Chateau, Sport, Premuim Audio (Logic 7), HUD, Cold Wx Pkg, SIRIUS Sat Radio, Delivered w/CIP 15.2, Aux Input, using Cingular Motorola v551 (v557 as of 1/7/06) Bluetooth implementation w/ snap in adapter, V1 - not hardwired. Status Born on 1/25/05, baby delivered 2/25/05, broken in 3/25/05 Upgrade to CIP 16.2 on 3/15/05, upgrade to CIP 20.02 on 3/17/06 w/MP3 enabled - Great, great BMW!!

[bruce12861]

THANKS JUST WHAT I WAS LOOKING FOR!

[bruce12861]

[bruce12861]

[naveedafridi]

On my M3's when I use Axxis Ultimate pads I get the same problem. If I brake hard a few times it goes away.

Could the 6 series have a harder brake pad compound and a slight glaze on its surface gets it to squeek?

Just a thought -

Is it worth bedding them in
Bedding in brakes

[bmwlex]

i have around 19k miles and brakes started making noise, not exactly squeeling, more subtle at low speed. it was time for an oil change and had the dealer check it out at the same time. result was the replacement of all the pads, sensors and linings (!?)(part 34-11-6-767-191). Seems ok now.
-lex-lex
2005 645ci coupe black sapphire/beige/sport/winter/logic7/ 904 build

[cobradav]

Did you happen to notice what mileage your Condition Based Service (CBS) said about your front and rear brakes had remaining?

I am currently at 34,500 miles with CBS claiming the fronts still have ANOTHER 38,000 miles left and the rears 46,000 miles. No unusual sounds or action. Needless to say I have been suspicious that I can be that gentle on brakes (although I am very easy on them) and I have the service department check them each time I am in. They tell me I have not reached 50% wear yet.

_______
US '05 645 Coupe, Silver Grey, Chateau, Sport, Logic 7, HUD, Cold Wx Pkg, SIRIUS Sat Radio, Aux Input, Bluetooth w/ snap in adapter, V1 CIP 20.02 w/MP3 enabled - Great, great BMW!!

[bmwlex]

sorry didn't notice and of course it has been reset. the cbs did say i needed lof, microfilter and brake flush, they did the brakes to get rid of the noise. i do a lot of stop/go.-lex
2005 645ci coupe black sapphire/beige/sport/winter/logic7/ 904 build

[cobradav]

Apparently mine is more go than stop:)

Brake Flush and mocrofilter will be my next scheduled maintenance. I'll have them check my pads again.
_______
US '05 645 Coupe, Silver Grey, Chateau, Sport, Logic 7, HUD, Cold Wx Pkg, SIRIUS Sat Radio, Aux Input, Bluetooth w/ snap in adapter, V1 CIP 20.02 w/MP3 enabled - Great, great BMW!!