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Hi Gang,

After I bought my favorite toy last year, I was disappointed to discover the well-known rear brake noise problem. Well of course, I went to the dealer who offered limited solutions. I tried the EBC brake pads. This fixed the noise but because the EBC pads are thicker than the stock pads, they would rub against the rotor and create a different noise. Once again, back to the dealer who installed new BMW pads and also a new rotor. All this was on the dealer’s dime, no charge. Everything was fine again. No noise for several hundred miles; then it started again.

The problem, as I see it, is this – after some miles and stops, the stock pads actually put a mirror like finish on the rear rotor. This causes the pads to chatter when the brakes are applied and the wheel is turning slowly. This doesn’t occur on the front brakes because the rotors are perforated. So, I tried an unconventional solution. I put the bike on the center stand, started the engine and put the bike in first gear so the rear wheel would spin at a low speed. With my handy Dremel tool I put the flat side of an emery disk against the rear rotor where it was worn smooth. I burnished this area lightly to remove the shine and roughen the surface. This works on the right side of the bike, but on the left side I had to stop the wheel and work the area between the spokes. Again, only using the flat part of the emery disk. I’m not cutting deep groves or removing a measurable amount of the rotor, only removing the shine. The whole procedure took a few minutes at most.

That was several hundred miles ago and no noise, the brakes work great. I know in time I will need to repeat this process. I’m sure there are other ways to remove this glazing but the Dremel and a disk sure seems to work.

Bob Smith
’05 Dark Graphite
 

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You're on the right track, cementite is the culprit. (almost as hard as diamonds and what you are removing).

This is a lengthy article and talks mostly about "warped" rotors, but halfway through it gets into more detail specifically regarding uneven buildup on the face of the rotor.

http://stoptech.com/tech_info/wp_warped_brakedisk.shtml

I removed my 20,000 mile rear rotor and cleaned it with a palm sander and garnet paper on both sides before installing new OEM pads and bedding them in the RIGHT way. I also rubbed in some graphite with my fingers. I'm at 23,500 miles after this with no more "fingernails on the chalkboard."

I too went through 3 disc/pad changes at my BMW dealer at their cost without any results. A waste of time.
 

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the problem is not the brakes or the pads, its proper bedding procedure. Same thing with high performance auto brakes.


F
 

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Possible new discovery?!

Almost 40K miles with EBC pads, both sintered and non-sintered EBC . . . not a sound out of either.

At our tech session yesterday, we replaced two sets of OEM pads with EBCs. Too early to report a success, but I'm guessing they will report back with good news.

After yesterday, I do have a new suspicion with the rear OEM pads however. I noticed that both sets of OEM pads that we removed had a noticeable ridge at the top of the pad where the pads where obviously riding at the edge of the rotor. I am starting to wonder if this isn't the culprit of the noise. Could the pads be scraping and squealing along the edge of the rotor?! Makes sense to me. I'm betting that if one would grind a beveled edge into the pad material (where it meets the edge of the rotor) that all the sound/noise would diminish.

Then again . . . maybe I'm full of crap. :D
 

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Just back from 200 miles on the new pads

messenger13 said:
Almost 40K miles with EBC pads, both sintered and non-sintered EBC . . . not a sound out of either.

At our tech session yesterday, we replaced two sets of OEM pads with EBCs. Too early to report a success, but I'm guessing they will report back with good news...
I noticed a little noise from the new rear EBC pads sometimes when I stopped, but not every time. Much better than it was before, but still there -- a little... sometimes.

So... do I need to do something to break in the pads? How do I do it?
 

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Rear Brake Embarassment

My new LT has only 800 miles on the clock and the dreaded rear brake whine has already started. I spoke to the dealer who fixed it by saying - "it's an LT trait - nothing can be done - just live with it"! I'll try the dremmel!

Regards
Birdman :rolleyes:
 

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When I put on the EBC pads, I took the bike out to a stretch of straight lonely road and made a series of hard braking stops from highway speed. There is a ton of info on the web about bedding them in properly and safely. Without the procedure there is a risk that you may have little or no braking with the new pads.
 

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When I stopped trying to fix mine & just started using them, the noise went away.
 

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BMW Brakes

Replace both front and rear pads at CCR with OEM BMW pads.
I've been riding it like I stole it with no special break in procedures,

Not a sound. :yeah:

28K on the rotor . . . :bmw:
 

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For what its worth my brake squeal was bad whether I used the brakes or used the brakes and try to avoid the squeal. So I asked a auto parts guy about it he had me try using "ultra disc brake caliper lube" the same stuff you would dress your cars brakes with. All you do is coat the BACK side of your brake shoe heavily and reinstall that is it. I admit I havent heard the squeal for around 1400mi but my brake pads were close to being gone so I am going to try on my next set of pads. A small tube of the stuff is only around 1-2.00$ I bought a jar for 6.00$
 

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The dealer tried the lube on mine when it was new. Lasted about half way home. I think you are on to something with the half worn pads, my noise went away somewhere between 25,000 & 30,000 miles. When everyone is chunking the OEM pads for EBC pads, I'll take the half worn OEM's.
 

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My 06 had the squeal until I did an ERC with the emergency stops that really opened both my and the instructors eyes!! He had never seen a bike stop RIGHT NOW like the LT. Even the crotch rockets were sliding the rear tire and couldn't stop as fast.

It seems the six or eight panic stops have halted the brake noise for the last six months.
 

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Caution...

OK, ladies and gentlemen...

You can "bed in" your brake pads, even if you've spent the last year squealing like Rosie O'Donnel entering an all-you-can-eat dessert buffet.

Plenty of articles on the process, this is one of the better ones...written for cars, but the process is universal:

http://www.zeckhausen.com/bedding_in_brakes.htm


HOWEVER...

Do NOT do this unless and until you have done the following:

1. make absolutely certain that you are wearing full protective gear, and in an area as free as possible of traffic and pedestrians

2. Before each run, look at your dash at the abs brake warning lights

3. realize that just because the abs warning lights are not flashing (and this is after you have ridden from start-up of course), this does NOT guarantee that your abs is functioning...there can be any number of failures, and only YOU can guarantee your safety.

4. best to take a series of controlled runs before this to bring rear-wheel braking up to the point of "almost initiating ABS, but not quite" DO NOT jump right into this and expect not to light up your LT's safety braking system if you have not practiced it

5. Critical to the "bedding in" process is NOT TO apply the rear brake after really heating them up until completely cool, as not to sear pad material onto the disk (see the article I linked above). If you've never come to a stop using only your front brakes, you'd damn well better practice that before doing this, in case something goes awry here--whether that be an animal jumping out, or rear brake failure, or a mistake. Going down ain't fun.

6. Before making your bedding-in runs, ride the ENTIRE length of your ride a couple times and survey for loose road, gravel, fluids, anything that could contribute to a crash

7. MOST IMPORTANT, do not, and I cannot stress this enough, DO NOT do this alone. If something goes bad, you want someone there to call for assistance. Does this make me sound too much like your mother? OK, guilty as charged...but personally, I'd rather have everyone on this site have squealing rear brakes than have ONE of us get hurt and have no one there to make sure they get medical attention, so make fun if you will!



Pete
 

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grifscoots said:
Good grief, Pete. You make bedding pads sound scary. Next time I WILL bring my mother.

oh great, if you bring YOUR MOTHER, we'll have to post threads on how to replace blown rear suspension units!!!


sorry, had to take the shot!!!


Pete
 

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