Brake Problems

[wastntim]

Over the winter I installed SRT brakes on my 02RT. Put new rotars on the front. I ran a set of brakeman 3's on a couple early trackdays, but switched to stock pads all the way around for the rest of the season. I ran about 5 days since, with the latest being at viper days over the weekend. On Sunday at vdays, I ran two sessions, parked the car for an hour and loaded into the trailer. That night I replaced the front stock pads with pre-bedded brembo race pads.

When I replaced the stock pads I noticed that both both sets of fronts were worn at a significant angle. the next day I had the car at autobahn. As soon as I started to heat up the brakes the front of the car began to shudder under braking only. The hotter the brakes got the worse the vibration got. It got to the point that under heavy braking the front tires were losing grip under braking. I let the car cool ran one time and had the same results.

The general consensus was that my front rotars are warped. Ok here's the questions?
1) Do you think that warped rotars are likely to be the problem?
2) Would this be common on relatively new rotars ?(probably 3,000 miles total including seven track days & I am not an advanced driver and am probably pretty easy on brakes)
3) Is this likely to happen again and if so, would switching to better rotars help this?
4) Should I consider cooling ducts?
5) Is the uneven wear on the stock pads common?

Any help is appreciated.

 

[2002_Viper_GTS_ACR]

Come to daddy....

1. Check your wheels are still balanced correctly. (aka didn't throw a weight)
2. Make sure your wheels are not bent.
3. Check torque specs on all rotors (again)
4. Make sure those 'rebuilt' rotors are actually working correctly. Hopefully others can step in and explain how to validate all pistons are moving/actuating properly.
5. Make sure you got the RIGHT front rotors. (highly unlikely you got the wrong ones, but check).
6. Get us some photos of these pads, so we see what type of wear your talking about.
7. Why did you keep switching between pads, something else was telling you to do that, what were those 'initiators' you might have been jumping between pads to fix a problem that was NOT related to the pads. (aka more symptoms for us to use in diagnosis).
8. Uneven wear was never common on my gen 2 or gen 3s
9. Talk to Dave's Big Brake and ask him what he thinks.
10. Call the 'rebuilder' /supplier of the new rotors and see if they have any other cases/instances like this.

You're welcome for starting points.

Jon

 

[fireball]

I think this is an easy one. The problem is that you're switching pads of differing material. When brakes are 'bedded' you're transferring material from the pad to the rotor and it's this similar material to material friction that stops the car. Once bedded all is well. If you change pad material use an emery cloth on the rotors until the color changes, then bed the brakes like the rotors were new.

I went to a couple of seminars from Hawk brakes and this was discussed at length. The engineers suggestion was that you never change pad material without either changing rotors or 'freshening' up the rotor surface. It's critical that the pad material and the material embedded into the rotor be the same material. He also said that almost everytime someone thought their rotors were warped it was actually a thinkness change in the rotor caused by brake pad material deposits.

I'd start by cleaning up your rotors, bedding the brakes then see how it behaves.

This information has served me well in my race cars.

Greg

 

[SmoknTires]

I agree with fireball. When I emailed you last, didn't know you were switching between brake pad compounds. Can definitely have an effect. I experienced exatly this first hand too.

 

[wastntim]

Thanks for the replies. I will definately try cleaning up the rotars and retesting.

 

[Chuck 98 RT/10]

You said "new rotors" what brand? Regardless, check the rotors for cracks. Not the tiny little cracks, those are normal. The cracks to worry about are the ones that go all the way to the edge. If they go that far then that is your problem and you must get new rotors. Under any circumstances DO NOT DRIVE WITH A CRACKED ROTOR.

 

[Viper X]

I too agree with Fireball.

Doesn't sound like you cleaned up your rotors before switching pads. Not sure why you switched pads (unless they were worn out) as BM 3's work just fine on the street.

Cooling ducts work very well on the GTS / RT, I run them on my 01 GTS and would recommend them highly. Call JonB.

Dan

 

[SCLSSRT10]

Rob,

Give me a call next week to discuss. you added some information you didn't have on Monday when the problem showed up.

Steve

 

[wastntim]

Rotars are stock. Bought new this year.