Brake Squeak

[XCITsNU]

I still have a rotor shimmy at 70+ when appling the brakes. Anyone else getting this?

[DZeckhausen]

Originally Posted by srt42

Has anyone else noticed squeaking brakes when lightly applied? I've been letting them break-in a little and hoping the squeak would go away, but it's very loud and very annoying.

As soon as you get a chance, you should follow this brake bedding technique: http://www.zeckhausen.com/bedding_in_brakes.htm. If you want to understand why it makes a difference and exactly what is happening when you do the bedding, then read this: http://www.stoptech.com/whitepapers/bedintheory.htm

Despite what some others have said, there is nothing inherent about high performance brake systems that causes unwanted noise. This is not something you have to live with. The proper selection of friction compounds (pads) and the proper bedding of brakes will almost always cure a noise problem. It doesn't matter if you're driving a Honda with 9" rotors and 1-piston floating calipers, or a Mercedes E55 AMG with 14" rotors and 8-piston fixed calipers. Or a Porsche 911. With proper pads, installation and bedding techniques, your brakes can be noise free.

[XCITsNU]

Would his explain the VERY apperant vibrations when braking? I haven't tried this yet, but will find a safe place to give it a shot. Just curious if I have more to worry about here than just brake bedding...

[DZeckhausen]

Originally Posted by XCITsNU

Would his explain the VERY apperant vibrations when braking? I haven't tried this yet, but will find a safe place to give it a shot. Just curious if I have more to worry about here than just brake bedding...

Yes, this may explain your vibrations under braking. Most judder problems are caused by thickness variation. This variation is a result of uneven pad deposits on the rotors. Often, a good bedding session can reduce or eliminate judder. Just don't wait too long or your rotors may end up permanently damaged.

This is good background reading to understand the phenomenon: http://www.stoptech.com/whitepapers/...otors_myth.htm

[srt42]

Originally Posted by DZeckhausen

As soon as you get a chance, you should follow this brake bedding technique: http://www.zeckhausen.com/bedding_in_brakes.htm. If you want to understand why it makes a difference and exactly what is happening when you do the bedding, then read this: http://www.stoptech.com/whitepapers/bedintheory.htm

Despite what some others have said, there is nothing inherent about high performance brake systems that causes unwanted noise. This is not something you have to live with. The proper selection of friction compounds (pads) and the proper bedding of brakes will almost always cure a noise problem. It doesn't matter if you're driving a Honda with 9" rotors and 1-piston floating calipers, or a Mercedes E55 AMG with 14" rotors and 8-piston fixed calipers. Or a Porsche 911. With proper pads, installation and bedding techniques, your brakes can be noise free.

Well, I gave your procedure a try today and this is the second seating attempt with virtually no help. I tried the other one mentioned before your post. The right front continues to squeak. It's loud, annoying, and cheesy. I may have to try the seating another time or 2 as you stated in your post (if I have any pads left).

[DZeckhausen]

Originally Posted by srt42

Well, I gave your procedure a try today and this is the second seating attempt with virtually no help. I tried the other one mentioned before your post. The right front continues to squeak. It's loud, annoying, and cheesy. I may have to try the seating another time or 2 as you stated in your post (if I have any pads left).

When you performed the bedding procedure, did you complete at least 6 aggressive slow-down events without ANY cooling off period in between? In other words, did you follow each event with an immediate, full throttle acceleration back up to 60 mph and then apply the brakes again?

I see many people botch the bedding procedure because they think they can do a couple slowdowns here, then cruise around for a little while, do another couple, and finally finish up when they find a third spot of low traffic density. It doesn't work that way. If you break up the bedding session into three distinct parts, it's as if you did nothing at all. The key is to get your rotors hot enough to get a transfer layer of pad material onto the rotors. This temperature isn't reached until about the 5th or 6th slowdown. Each time you accelerate back up to 60 mph, it's a race against time. Your rotors are cooling off as fast as they can and you're trying to get back up to speed before they do so. Each stop gets the rotors hotter than the stop before as long as you don't allow any time between stops to cool off.

If your right front pad is the one doing the squealing, then there's something different about that pad, caliper or rotor from the left side. The most likely difference is that there's only a partial transfer layer. It is possible that the tolerance of the pad backing plate is off slightly, allowing that pad to be a little looser than the left front and that lets it squeal more readily. But I'm inclined to think it's the bedding. Most everyone who rides along with me when I do it is surprised by how aggressive the technique is.

As I mentioned earlier, some pad compounds are more prone to squealing than others. If it turns out this is the case with the factory SRT8 pads, we should be able to offer alternative, lower noise pads once we figure out the proper sizing. This should happen as soon as jketron gets his brakes measured at StopTech. See: Anyone near Los Angeles with an SRT8 we can measure for a BBK (Bigger Brake Kit)?

[srt42]

Yes, I got about 6 or 7 quick bedding events in before traffic came up behind me. There was a very small delay before I finished the last event.

[DZeckhausen]

Originally Posted by srt42

Yes, I got about 6 or 7 quick bedding events in before traffic came up behind me. There was a very small delay before I finished the last event.

And each "event" was a full, threshold brake from 60 mph down to about 10-15 mph? Threshold brake means you were just on the verge of engaging ABS. If so, then you did it right. Did you see any smoke coming from the wheels? Any strong brake smells? Do the rotors now have a light gray haze on them?

[srt42]

I did not see or smell any brake smoke, but IMO I applied the brakes hard, just shy of slamming them on. I felt very slight sways to the left and right when braking. It was dark by the time I got home and I did not check for material on the rotors. I'll check it today. I may not have been aggressive enough. I felt like I was aggressive, but my aggressive and your aggressive may be very different.

[JMatt]

I followed the directions exactly this morning in my 911. I was braking and accelerating so hard in between that on about the 8th time I thought I was going to throw up from motion sickness. (Seriously - for some reason high deceleration makes me sick).

Got to work and pulled up to the gate at the garage to swipe my pass - no squeal. None. The question that remains, is how long will this last before they start sqealing again? One day? Week? Month?