Really bad brake shaking.

[norcalpb]

Hello all,

My last 2 track days I’ve been getting some serious vibration from the brake pedal once the brakes get hot. The shaking only seems to be coming from the front.

I have DTC-30, centric rotors, and dot 4 fluid.

After my first day of shaking I replaced all 4 rotors and swapped fluid afterwards but the shaking is still there starting on like the 3rd lap. The first 2 laps I can slam on the brakes and it’s super smooth coming to a stop.

Does anyone know what this could be?

TIA
Steve

[x808drifter]

Take the first set of rotors and see if they are still true.

[NoHaveMSG]

Can you post of pic of your rotors? My car would do this with XP10's. It would develop so much pad deposit it would shudder hard under braking.

Here is what mine looked like.

[norcalpb]

Originally Posted by x808drifter

Take the first set of rotors and see if they are still true.

Unfortunately I threw them away last month. They weren’t true, I could feel waves on the rotor face without even pushing that hard. At Laguna Seca I would get them so hot they almost seemed to temporarily straighten up and the shaking would stop.

I’m thinking my pads are worn in the same manner my old rotors were, and I just need to go crazy on a future brake bedding session? I’ve done one minor bedding session, but haven’t gone any harder than that as I don’t want to catch California on fire with sparks/lack of rain.

[norcalpb]

Originally Posted by NoHaveMSG

Can you post of pic of your rotors? My car would do this with XP10's. It would develop so much pad deposit it would shudder hard under braking.

Here is what mine looked like.

Yeah they don’t look good lol. One track day and like 2k street miles on these. Is 2021 the year I finally cough up the $ for a BBK??

[NoHaveMSG]

Looks like the pad smeared on the rotor. Rebedding them should make it go away, always worked for me. You may need to add ducting in the future or go to a more robust pad.

[norcalpb]

Originally Posted by NoHaveMSG

Looks like the pad smeared on the rotor. Rebedding them should make it go away, always worked for me. You may need to add ducting in the future or go to a more robust pad.

Yes I agree about adding a more robust pad. I should have went with DTC-60, but I must say the DTC-30 is quite usable on the street which is mainly what I use my BRZ for.

I have Rooducts brake ducts which are similar to the GT3 ducts, but do you think something like the Verus ducts would be worth going to before upgrading to a bbk?

[NoHaveMSG]

I am not familiar with Hawk pads, if the 30 is a mild pad that is probably mostly the problem. Most street/track hybrid pads just don't hold up once you get faster on a good tire. I am not super familiar with the effects of different brake ducts since I have never run them, I went BBK pretty early in on my tracking adventure.

[norcalpb]

Originally Posted by NoHaveMSG

I am not familiar with Hawk pads, if the 30 is a mild pad that is probably mostly the problem. Most street/track hybrid pads just don't hold up once you get faster on a good tire. I am not super familiar with the effects of different brake ducts since I have never run them, I went BBK pretty early in on my tracking adventure.

What is strange is that I have used less intense pads than the DTC-30 on the track (EBC Yellowstuff and Carbotech AX6) and there was no shaking but a poisonous-like metal burning smell that could be smelled by the people behind me. Brakes have been the hardest thing for me to learn in terms of tracking.

I'll re-bed the brakes and post pictures of the rotors soon.

[NoHaveMSG]

Originally Posted by norcalpb

What is strange is that I have used less intense pads than the DTC-30 on the track (EBC Yellowstuff and Carbotech AX6) and there was no shaking but a poisonous-like metal burning smell that could be smelled by the people behind me. Brakes have been the hardest thing for me to learn in terms of tracking.

I'll re-bed the brakes and post pictures of the rotors soon.

The PMU HC800's I first ran would behave like that. They would smell but never deposited material on the rotors. They would just only last 4 days.

[strat61caster]

+1 smeared pad deposits

always heard mixed reviews about Hawk so I've stayed away from the brand

[DarkPira7e]

Pretty sure you're braking so hard that you're stopping the earth's rotation, hence the strange feeling. All is well, just maybe lighten up on the pedal a smidgen.

[norcalpb]

Originally Posted by DarkPira7e

Pretty sure you're braking so hard that you're stopping the earth's rotation, hence the strange feeling. All is well, just maybe lighten up on the pedal a smidgen.

Lol yes when they are in “shake mode” luckily I can brake lighter and earlier and still get through the day.

[jflogerzi]

Get 2 sets of pads. 1 for street and 1 for track. Talk to Mike at CSG. If you can get 2 sets of rotors as well as blanks are cheap and just swap before track days. It's a pita but might save you from going to a bbk

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