will69camaro

iTrader: (19)

After my recent track day, I find my brakes are quite soft and a strange noise/vibration on moderate/hard braking. The vibration is much faster than what I would expect from a warped rotor. Brakes are stock w/ slotted front discs and HP+ in front and HP-S rear with stainless lines front and rear. The brakes are soft to the point of going almost all the way to the floor on most stops and easily able to push them to the floor if i want. Wasn't a problem before the track day.

Also, I have bled the entire system and went back and flushed the system after the bleeding didn't work. I'm using Super blue fluid if that has any effect on any advice you could give me.

What should I check next?

Thanks,
William

Mojave

iTrader: (4)

How are your pads wearing? If they are tapered, your calipers have spread. Very common problem with 98+ brakes. Also, check to make sure the pads are sliding freely in the sliders and the guide pins are moving freely and are well greased. Also, check your front wheel bearings. Worn bearings can lead to pad knock back which leads to a long pedal.

As far as the vibration, rotors seem like a good place to start. Part store cheapies work just fine, and you will need them eventually if you start running real pads.

Also, HP+ aren't really up to serious HPDE abuse. I would consider switching to a real pad like a Hawk HT10, HT14, DTC70, or a Carbotech XP10 or XP12 for the front, while leaving less aggressive pads in the rear to avoid axle hop under braking.

SouthFL.02.SS

You have uneven pad compound buildup on the rotors from the not-up-to-the-task HP Plus and HPS pads causing the vibration. Also, the pads must have glazed over, causing the soft brake feel (they're not biting anymore).

1) If you plan on using these pads a while longer for street use, bed them in again. Do several hard stops from 60-80mph to a crawl, over and over, about half a dozen times. This should clean the rotors and unglaze the pads somewhat.

or

2) You can change up to a race compound and do the same process if you plan to keep race pads on instead. The race pad will likely clean the rotors even better.

or

3) You can have a shop turn the rotors, but you will lose precious rotor thickness in the process.


The HP Plus does fine for track days on lighter cars (like my RX-8), but it's not enough pad for a Camaro. The pads Mojave mentioned are all great choices.

will69camaro

iTrader: (19)

I will check the pads, all looked good on quick inspection. The sliders work well and I began to assume part of the problem might reside in the stock 100k mile wheel bearings getting some abuse.

I was hoping the HP+ would do for a street/track pad since I didn't want to have to run a dedicated track pad but I will now consider replacing them for track duty with a more aggressive pad. Lighter pads will definitely be left on the rear as I already am having bad axle hop under braking. If i can get the car to have at least a consistent pedal then I will go about bedding in the brakes again. As it is, it's hard to make a hard stop period much less one from speed.

Thanks for the advice so far guys I'm very new at this but enjoying every bit of this racing that requires steering input as opposed to my roots with straight line racing

William

mullenh

iTrader: (1)

there are aftermarket pads with a far more aggressive bite than the stock pads you are using. They make them for all kinds of racing applications. Some won't work at all untill you heat them up and others ...etc.. The down side is the more aggressive a pad you choose the faster it will eat your rotors and dust will be bad. But personally I like being able to stop. U.S. brake makes a road racing pad and there is probably a sponor here.

mullenh

iTrader: (1)

ABS will cause the rotors to feel like they are vibrating. If it is not the ABS system you are talking about, then warped or rotors that are to thin will vibrate too. There are aftermarket pads with a far more aggressive bite than stock pads. I am not familiar with the HP+ and HP-. They make them for all kinds of racing applications. Some won't work at all untill you heat them up and others ...etc.. The down side is the more aggressive a pad you choose the faster it will eat your rotors (rotors will vibrate) and dust will be bad. But personally I like being able to stop. U.S. brake makes a road racing pad and there is probably a sponor here. As for the fluid I would use regular DOT 3. One other thing you mentioned stainless steel lines, I would guess that you replaced your brake lines from that comment. Make sure that the lines do not route to close to your headers, if they do get some sort of heat shield.

mikespeed95

iTrader: (1)

probably user error, you tend to have a problem with making things soft.

will69camaro

iTrader: (19)

New master cylinder solved the soft pedal problem and the vibration has been narrowed down to pad deposits being left under the pad. I cleaned everything very well and all is back to fully functioning braking system. Thanks for the help and I'm sure I'll have more questions in the future.

EchoMirage

iTrader: (3)

i think if you run brake ducts, the HP+ will last longer and not fade as much

will69camaro

iTrader: (19)

I have been thinking about making brake ducts for it but I wasn't braking hard enough to get into much fade. I got very little fade when I was on track. My car has a few things yet to be where I'd want it to be but that's always the case. I'm considering picking up a cheap LT1 and prepping it to CMC specs. We will see however.

William

EchoMirage

iTrader: (3)

id rather buy another car to use as any kind of racer, like you want. if you plan on any kind of sanctioned car vs. car racing, you really dont want your pride and joy driver/weekend cruiser banged into by some ******* who picked up a $3k gutted LT1.

either way, from what ive heard, brake ducts are almost mandatory for even just a track day. you can do it without, but with ducts it will greatly increase your rotor and pad life, not to mention cool them enough for proper braking. you may think youre not getting into the brake very hard, but keep in mind youve got almost 2 tons of weight coming down from what, 40, 60, 80, maybe faster? plus the repeated use of brakes on a course as apposed to occasional use on the street wont allow them to properly cool. im working on my own ducting now, just in case i ever finally get to a track for some regular fun runs...no racing or whatever.

SouthFL.02.SS

Look into Cobalt Friction brake's GT Sport as a better alternative to the Hawk HP Plus.
http://www.cobaltfriction.com/compounds/

Even better would be the XR3 pad listed (it would need to be swapped out for street use however).

Again, HP Plus will definately be overwhelmed by the F-bod with any decent lap pace.

Mojave

iTrader: (4)

Brake ducts definitely help, but HP+ is NOT a track pad. Before doing ducts, I would step up to a real track pad.

RockRacer

I had good luck with Porterfield R4s at TWS. they are very grippy when warm. It would be wise to use better than average brake fluid too. something like ATE Superblue.

Disclaimer: I don't sell any of these products; just relating my experiences with them.

will69camaro

iTrader: (19)

I agree with the need to step up to a more agressive pad and have plans to maybe for the next event. I'm already using a better than OEM fluid. I have super Blue in the car right now. We will see what I do for the next track day.

Thanks for the tips guys!
William