[parptarf]

So I changed my rotors recently and mounted brand new Brembo pads yesterday. Drove all night and even had a guy who runs GT3 racing test my car. They worked perfect to say the least.



I went for a drive earlier and everything was alright then too, but suddently when going through slower traffic in town my brakes started vibrating like crazy. Somethimes they squeacked and somethimes they vibrated. But even in slow traffic it felt random so it wasn't doing this at every intersection. At hard breaking they work as usual.





I did not change the anti-vibration shims as they look brand new, but they are not glued to my new pads. Instead I got adviced to put copper paste on the back of my pads. Is that my problem? I need to clean both surfaces and put a new adhesive on the back of them?



Several other people I've talked to are running without glue and they're not having this issue.

Partial Post: Please Login or Register to read the full post.

[flash]

i just went through this on another car.



the first thing to do is make sure everything is tight.



the glue is not the issue. i've never used glue.



brake vibration is almost always uneven pad deposit, usually due to incorrect break in procedure, or the wrong pad choice for the application. the squeaking is high frequency vibration. unfortunately there is no way to completely get rid of that without changing parts.



you can try the pastes and stuff out there. they can cure the problem about 15% of the time.



you can try having the rotors surfaced, and install new pads. if it isn't too bad, that might do it.



about 60% of the time, i have had to start over with all new parts.



follow the break in procedure at the stop-tech website, regardless of which route you go.

Partial Post: Please Login or Register to read the full post.

[parptarf]

New parts would be pretty bad I have just installed everything(Pads yesterday and rotors 1 week ago) And they should be compatible. Sebro drilled rotors and Brembo brake pads.



I'll check out the break in procedure though. Hopefully that works.

Partial Post: Please Login or Register to read the full post.

[flash]

if you didn't follow the correct break in procedure, you can ruin pads and rotors in 10 minutes. happens all the time.



once the deposits are formed, there is almost no way to get rid of them completely. there are some short term things that work sometimes, but the problem always comes back.



as a starting point, definitely at least takes some 220 sandpaper to the rotors and pads until you completely remove all signs of deposit or glazing.



do not attempt to merely break in the pads at this point. you must first remove the deposits. attempting to break them in now will only make it worse.

Partial Post: Please Login or Register to read the full post.

[tryan]

Yep, you need a thin layer of brake pad 'glaze' even across the face of the rotor. You should be able to tell by looking at the rotor.



Hard pads need to reach elevated temperatures to function correctly.... those first few stops will be longer.



The vibration is not your abs engaging? Maybe? I would wipe the sensor off if you take things apart.



One little trick that I employ is to never really stop after scrubbing off speed. If you have to stop for a light or traffic, stop short and let the car creep so the pads dont rest on the rotor in one spot. Heat raises the carbon to the surface which causes an area that is harder than the rest of the rotor.... most people think their rotor are warped but no. Turning them makes them pretty but new rotors are the real solution to get rid of the pulsation.

Partial Post: Please Login or Register to read the full post.

[parptarf]

My rotors doesn't look glazed so I went on a few twisties and did some hard breaking. Went till I felt a little fading then cooled off the brakes and went at it again. After that I went for a normal drive and everything was not only tight, but felt better than yesterday. No vibrations, at least for now. I'm probably gonna take the pads off again this weekend and check for glazing. I can survice new pads, as I still haven't gotten my rear rotors thus not changing the pads there.(So I have a set laying around) But new rotors up front would leave me without a car for at least a month. Which would be a crisis to say the least.



I cleaned the ABS sensor when I changed the rotors a week ago. And it doesn't feel at all like ABS.



I wish some of the "how-to's" I watched and read told me about the importanse of breaking the new parts in. :/

At least I won't make this mistake again.

Partial Post: Please Login or Register to read the full post.

[parptarf]

My pads are off now. There's no glaze on them either.





Could it be that I drove for a week using old pads on new rotors and that leaving deposits on my rotors?

Both the pads and the rotors look alright now, doesn't even resemple what I can see when searching up glaze.



Here's a picture

Partial Post: Please Login or Register to read the full post.

[flash]

it's possible. if so, count yourself very lucky.

Partial Post: Please Login or Register to read the full post.

[parptarf]

My rotors are looking great still. And went for a drive now. no squeaking or vibrations. Also dug up my old pads, they had some glazing on them.

Guess they were the cause of it all.





Oh man, that was close. Next time I'm not gonna use old pads on a new rotor and I'll break them in as fast as humanly possible.

Partial Post: Please Login or Register to read the full post.

[flash]

good call

Partial Post: Please Login or Register to read the full post.

[parptarf]

So yeah, unless you're Donal Duck's cousin. Don't do lik I did.

Partial Post: Please Login or Register to read the full post.

[parptarf]

And it's back. But not nearly as bad as before. Had a couple mild breakings over the last few days with some vibration in my pedal and noise.

It's completely random but only in slow traffic or parking. No vibrations at hard breaking and it probably only happends in about 10% of all stops I do.



Again my front rotors are looking pristine. Shiny with normal wear only. No uneven spots or glazing as I can see. I haven't had my pads off today but I'm guessing they're alright like last time.

I'm failry certain my rotors are not causing this. And I'm pretty sure my pads aren't either. Also considering how randomly it happens. Uneven wear should be more constant, right?



So here are my probable causes:



My rear brakes. Old rotors, I mean REALLY old rotors. Rusted on the edges and very unevenly worn. Plus I can see a little glazing.

It might just be a coincident that they started vibrating the day after I changed my front pads.



Or it could be a bad anti-vibration shim. If I remember correctly one in teh right caliper didn't fit "as good" inside it's groove. And as they're not glued onto the pads, it might not sit as flat as it should.



Could air in the brake fluid cause this? Or maybe even the caliper itself?

Partial Post: Please Login or Register to read the full post.

[flash]

you usually can't actually see deposits, until they are really bad. it's a chemical thing. given that it went away and came back though, i'm betting that you only removed the surface stuff, and you have now redeposited.



by the way, a bunch of hard breaking until you feel fade is not how to break in your brakes. that's exactly how you screw them up. it's a progressive stopping, increasing speed, but never full stop nor full pedal. you want to heat them up evenly, but not to the point of fade. they need to cool down a bit between braking too. again, the stop tech site spells this out very nicely. when you are done, you should have a slight bluing to the rotors, but not smell the brakes much.



it's almost certainly not the shim pucks. i have never used glue on those on any car we have done, and never had a vibration problem, as long as the brakes were bedded properly.



air will not cause the problem. it can affect pedal feel though.



a caliper would only cause the problem if it were not going down evenly. this would also be accompanied by pulling though.



as a side note though, take a look at your caster blocks. if they are soggy or cracked, they could contribute to braking vibration.

Partial Post: Please Login or Register to read the full post.

[parptarf]

I followed the stop tech sites instructions fairly close, increasing speed but no fullstops. It said I might feel a tiny bit of fade right before cooling down for the second set, which I did. I also got that blueish color on the edge of the rotors and a tad bit of smell from the brakes. I might have chosen my words wrong earlier.



Still though, wouldn't that be less random? And wouldn't I feel it when braking normal? All my braking feels normal and this only happens the second before a complete stop. And even when coming to a stop it's still rare.

But if it is my rotors and pads. I will need new pads and need to clean and sand down my rotors?







I'll check out those caster blocks. And with those shims, if one is broken or doesn't sit right in the caliper, won't that cause vibrations randomly?

Partial Post: Please Login or Register to read the full post.

[flash]

no worries. if you followed the procedure, then they would bed correctly, assuming there were no deposits to begin with.



believe it or not, i had exactly the same thing going on with the SL550. brand new rotors and pads. didn't get to bed them correctly though (don't ask - still pissed about it). they were fine up until the last 25 feet of stopping. then they would squeal like a pig. squealing is vibration due to deposits. this started after only about 30 miles. i was never able to get rid of it. i tried everything too. i was going to have to change out the rotors and pads again. i sold the car instead.



as i said before, you can try sanding the rotor, and if that fails, try surfacing it. you can try taking a box cutter to the pads too, and scuff them up.



regarding the caster blocks, look closely at the rubber. you have a 92. those are well known for failing. the good news is that the later model replacements work better.



as for the shims. they are pretty jammed in there, and self locating, due to the part that goes into the piston. not much of a way for them to not sit right. if the new pads went in, it's a pretty safe bet that the pucks are in place. when they aren't, the pad doesn't want to slip in.

Partial Post: Please Login or Register to read the full post.

[parptarf]

Got it.



I took the right rotor off(Thank god this was easier to get off than the old one <img src="/forum/images/smilies/968/biggrin.png" class="smilie" alt="" /> )



Sanded it down with some gritty then finer sandpaper and roghened up the pads with some sand paper as well.





It feels like it's only coming from the right side, at least the sound is. So I'm not sure if I actually need to do the left side as that one hasn't made a sound yet.

Partial Post: Please Login or Register to read the full post.

[parptarf]

So for now my front brakes are still doing fine.



Bot my new rotors and pads installed at the rear and went out for my bedding in process. But coming home it looks like I've only bedded in the fronts again. The rears still have the "new rotor" pattern on them. Though they now have a slight wear from my brand new pads.



Are there something wrong with my rear calipers or am I just being paranoid here and this is normal? It seems like they're not actually doing much.

Partial Post: Please Login or Register to read the full post.

[flash]

hard to get the rears to bed using the stock bias valve. many of us have changed to the 5/33 valve, which applies more rear brake

Partial Post: Please Login or Register to read the full post.

[parptarf]

After a day of driving the "new" pattern is starting to rub off. Seems like it's fine then.

Partial Post: Please Login or Register to read the full post.