Stoptech brake problem

[jcaspar1]

I am posting this here as I have not gotten a respose from StopTech.
I have a set of Stoptech front brakes that I installed in my Viper last year. I have been using the Axxis Ultimate pads. I did the break-in then as directed getting smoking front pads and green fade. All has
been going well until two weeks ago when at my third track event since
the brakes, I started to get a rumble/vibration with braking. I quickly
pulled off to check pad depth which was fine. I continued driving and
continued to notice the sensation only under braking. The brakes still
work fine. I have always been careful after each session to not brake
till stopped until the brakes have cooled. From the StopTech FAQ's it seems I
may have uneven pad deposition on the rotors. They seem to have some
blueish areas of discoloration though these are not the shape of the
pads. On the street I get just a hint of rumble that increases with harder braking. I am wondering what I should do next?
Should I have the rotors turned? I ordered some club race pads (similar to Brakeman #3's) to try.
Should I just try breaking in these pads to see if I can clear the
deposition? Or do I need new rotors?
Thanks

 

[Chuck 98 RT/10]

I would scuff the rotors and try new pads. If the problem persist then have the rotors turned. Are these the two-piece rotors or one-piece?

 

[REDSLED]

I agree with Chuck on this one. Had the same issue with my Stop Techs a while back. Scuffed the rotors and was back in business. I believe John Dearing had the same issue during OTC last week. It's a quick fix.

 

[Steve-Indy]

Jeff, this may help...easy to use..."3M Brake Rotor Surfacing Discs" part # 01410..just add an electric drill and you will be ready.

 

[jrkermode]

I have StopTech fronts with BM3 pads and I had the same issue, even a little kick-back in the pedal (like I could feel the slots in the rotors).

I immediately pulled in, checked everything out then discussed the matter with some other StopTech users. Apparently, this is quite common.

So, I went back on the track and "drove" through it. The rumble and the kick-back went away during the next session.

The rotors still look ugly, like they have tree rings, but everything works fine.

Hopefully, StopTech will chime in on this thread.

 

[StopTech Service]

Likely StopTech Issue

Jeff-

First off, my apologies for not responding more quickly to your e-mails. I could go into all the things that have blind sided me over the past few working days, but none should have prevented at least an acknowledgement. Not how we usually handle our Customer Service here at StopTech.

Your vibration is being caused by un-even pad deposition due to overheating the AXXIS Ultimate pads by using them on the track. We specifically recommend the Ultimate pads not be used on an open track; I'd say your first 2 times you got lucky. Sometimes driving more passively, not aggressively, will allow the pads to smooth out some of the vibration. We usually recommend a much more aggressive pad to accelerate wearing off the uneven pad deposits. We have a program where we send a set of Hawk Blue 9012 pads that fit our calipers. We charge for the pads when they ship, and will refund all but $50.00 if the pads are returned within a few weeks.

The Hawk 9012 pads are very abrasive when cold, so a series of aggressive braking manuevers, say 3 slow downs from 60-70 down to 30mph is recommended. Do the 3 stops in succession, the allow the brakes to cool with a few minutes of driving before doing another series of 3 slow downs. You do not want to get the pads so hot they start to transfer material onto the rotor. Typically around 10 cycles of stops will show a significant change in the vibration.

Once the vibration has abated, immediately remove the pads from service as running them on the street even a few days can wear out a set of rotors. There is also a pretty good amount of metallic dust to be cleaned and you don't want it to sit very long, especially if it gets wet.

There are numerous pads available for our ST-40 calipers, and our recommendation is to change pads between street and track or you will live with substantial compromises in both venues. Every time you change pads you need to re-bed the brakes, even when going back to previously used pads. To be honest, rotors do not like having different pad compounds run on them, however careful and dedicated bed-in with each pad swap will manage it pretty well. We can discuss pads best suited to your specific needs later on.

The vibration is due to the pad breaking down when over-heated and creating very slight high spots on the rotor face. The uneven "splotches" you describe on the rotor face are these uneven deposits. As the brakes are applied, the pad starts to skip over the high spots, increasing the deposit thickness in that area and also creating localized hot spots. In the worse case scenario, the hot spots can become hard spots due to the metallurgy of the cast iron changing in those areas. If that is the case, the vibration will be a chronic issue. This typically happens from agressive track use once the vibration has started.

There are several articles on the Technical Page of our website dealing with how brakes work. Of particular intrest on bed-in is an article titled "The Warped Brake Disc and Other Mysteries of the Braking System" Reading and understanding the concepts in this article will help you for the rest of your track driving career. Hers ia a link to the Technical Page:

StopTech Technical Page

Again, I apologize for the delayed response, but now the information can be more readily shared. Please get in touch and I promise to get back to you and we can discuss your situation in more detail.

Matt Weiss
StopTech

 

[jcaspar1]

Re: Likely StopTech Issue

Matt,
Thanks for your great information. I have always had great support from you guys. I only emailed you a few days ago so it has not been long, just my impatience. The Hawk pads sound like a great offer. I will be in contact.

Thanks to all else for the great suggestions and advice. I take this occurance as a good sign that I am actually starting to use my brakes on the track!

 

[jcaspar1]

Re: Likely StopTech Issue

Just wanted to give some follow-up. I followed Matt's advice using the Hawk pads and this has completely elliminted the problem. I have installed StopTech Club Race pads which do squeek quite a bit but hopefully will be a better compromise for street and track than the Axxis Ultimate pads were.

Thanks again to Matt and StopTech for their usual outstanding service!

 

[ViperRay]

Re: Likely StopTech Issue

Why not just remove the brake pad material with a 3M pad like when you "scuff" the rotors when we change brake pad material (rather than putting on Hawk pads)?

 

[jcaspar1]

Re: Likely StopTech Issue

Why not just remove the brake pad material with a 3M pad like when you "scuff" the rotors when we change brake pad material (rather than putting on Hawk pads)?

I don't know if that would work with "warped rotors" like I had, where there is enough material deposited that you get severe vibration on braking. The Hawk pads were easier as I didn't have to remove the front rotors (I figure you must need to do that to resurface the insides). Has anyone had good luck treating such a problem with the 3M Pad?

 

[ViperRay]

Re: Likely StopTech Issue

If your rotors were warped, you would have had to replace them. Apparently just too much pad deposition on focal spots on the rotor. The 3M pad is not difficult using the drill attachment but perhaps using the Hawk pads is easier.

 

[jcaspar1]

Re: Likely StopTech Issue

I put the warped rotors in ""'s as they felt warped but just had uneven pad depostion ala this StopTech article.