Cbntmn

Just had my fluids replaced. they used a synthetic brake fluid. When i went to put the pads on i pulled some old pads out of the tool box (my carbotechs didnt come in on time) and im really not sure what pads i put on. I have a stack of em and after they are used i cant tell if they are some hawks or some stock pads. I had some hawks but they only had about 1/4 of the pad left.

So i stuck em on. Got to the track and immediatly noticed that my brakes had no where near the grip from when i had the hawk dt70s on. in fact i had my pedal all the way down a couple of times under hard braking. Should it be this big of a difference??

Then on the way home i noticed that I can push my brake pedal all the way down, and then if i pump it a few times it becomes much tougher to push down. Not sure if it is always this way or not.

Maybe the fluid change was not done right? do the pads make that much of a difference??

When mine was set up with the hawks i drove one with the wilwood set up of rotors and calipers. I have to say the wilwood was nice, but mine stopped just as well (for 5k less) with the hawks on it. In fact i could go just as deep into turn one as he could with my set up.

Just need some input because the fluid and the pads took place at one time. I dont like haveing to push em down that hard to get me to stop.

Good side is with those brakes and with worn 710s i ran my best lap times ever. 1.19.3 is 1.1 seconds better than my best.

Bill Dearborn

You should feel a huge difference between a race pad and stock pads. The race pads have a lot more braking torque than street pads. As for the pedal travel you could have air in the lines but I suspect pad taper since you do not seem to be a novice when it comes to bleeding the brakes. You were using used pads and they probably were tapered to begin with. Then with some additional usage they tapered even more. From my experience the street pads tend to taper a lot quicker than race pads. The taper along with the normal pad knockback caused the increased pedal travel which probably seemed to get worse with each succeeding session.

Bill

Cbntmn

Thanks Bill.

The brakes where bled at the local chev dealer by their "vette specialist" I had them replace all of the fluids except coolent.

I hope the other pads take care of it. I have carbotechs in the mail and I think ill install them and find a empty road and test em out before my next event. If thats not it ill have the brakes re bled. Really missed that stopping power this last weekend, and while the hawks eat up my rotors i dont mind spending the 50 bucks for rotors for the security of staying on the track.

varkwso

I am with Bill - I would credit pad taper and knockback. It is a common C5 affliction. Used pads are especially bad if you mix the pairs up.

I end up bleeding my synthetic fluid almost everyday at the track...

Cbntmn

Wow. Every time?

I have never had to do that before. In fact the old fluid had 5 track days on it and it never fadded.

I guess we will see when the new carbotechs come. Hopefully it will get back to where it was. I shoulda just left good enough alone...

Z06cool

[QUOTE=Cbntmn;1559110731]Wow. Every time?

QUOTE]

Yep. End of the first day on two-day events and after every pad change about 4-5 pumps. I installed some solo/speed bleeders so it doesn't require two people to bleed the brakes.

Bill Dearborn

I always bleed mine a day or two before an event and never touch them while at the event even if I have to change pads or rotors. Never had a problem.

Bill

varkwso

CMP, Rd Atl, Sebring and Rockingham it is daily - sometimes twice daily depending on how fresh the pads are. Roebling, Barber and VIR I can sometimes make it two days depending on track time, track/car conditions and whether I am chasing TimZO6 or Robroot....

AU N EGL

How old are your calipers?

Older calipers have spead slightly and that causes brake fade too.

As others have said, Brake fluid must be flushed right before EACH event, or with in a week prior to an event.

and in many cases the night between days and as Vark Mentioned if you run hard and brake hard, between runs too.

Cbntmn

Calipers are stock. Car has 11k miles. Its an 03.
Rarely driven on the street in the last two years and not driven hard on the street.

I really dont feel good about flushing fluid at the event but it sounds like its something i need to learn how to do.

Where do i get the speed bleeders?

Im pissed because they were amazing brakes before this weekend. Ill put the carbotechs on Monday and go run it and see how it does. If its still not right ill flush the fluid. If its still not right then its wilwood caliper time.

AU N EGL

Brakes used hard one weekend does not mean they last. Need some great DOT 4 brake fluid. ATE Super Blue, Super gold 600 ( same as blue only gold ) Motul, Willwood 600 and of course Castrol SRF.

Speed bleeders are not the best option as they dont open up the ABS modual for the brake fluid.

a Motive Power bleeder pushes the brake fluid though.

varkwso

It takes about 5 mins to do - once you get the wheels off - there is always someone around to help you push the pedal. You may have gotten the fluid hot enough to boil and have a few bubbles (compressible gas) in your eagerness to get down to 1:16s. I do not think you need Wilwoods just yet.

Cbntmn

I think my rotors are getting a little cooked also. Starting to surface crack so its off to napa...

I was supposed to have castrol synthetic in there.

It really wasnt that the brakes got worse over time, its just that they were never that good from the start. Makes me believe I either had a little air in the line to start with OR the pads i put on just SUCKED.

Ill try the carbo's first. It they still suck ill bleed em off and get some Motul. When i raced bikes is was sponsered by Motul. They make great stuff.

Z06cool

AU N EGL, I use Earl's Solo Bleeder Screws. Got 'em from LGM.
http://www.lgmotorsports.com/catalog...2806a575c76c4d

Thought I was doing fine using these. Wouldn't this accomplish the same thing as a two person job? One pumps the brakes and the other opens and closes the bleeder valve. Wouldn't this pass through the ABS module also? Just trying to learn.

Sidney004

I am a big fan of speedbleeders as well. Be sure to get the "speedbleeder bag" so you can observe the fluid condition as to bubbles and color. It works as advertised.
www.speedbleeder.com

AU N EGL

I am failerly sure that it will.

ErnieN85

As long as the key is off the valves in the abs/esc are centered and all fluid will flow through.
You will only need to use a techII if you get air trapped in the unit and then it is necessary to cycle it to get all the passageways flushed (remove the bubble).

AU N EGL

Ok then, the pressure bleeded would be best. After hard driving and braking there will be bubbles in the system, Bleeding helps rid those bubbles and puts fresh fluid into the caliper.

The pressure bleeder, Motive, opens up the ABS with the back pressure.

ErnieN85

Could be I've never got mine that hot though
There are a whole lot of things that we do on the track that aren't covered by the service books or GM's training either!

AU N EGL

Service books ??? GM Training???



Some one told me that the Service book says it takes 3 hours to change brake pads and rotors or something like that.

How may guys here can change all four rotors, all the pads and do a full fluid flush in under an hour? wait, I mean between sessions ??
that also encludes changing 4 wheels too.