GO-FIGHT-KILL

I went to CMP this weekend, the first day the car did great, no boiling at all. After the third session of the day, I got in my car to drive back to the hotel, and ZERO brakes. We bled them, and they were fine, back to locking up the seat belt.

First session of the second day, I had to bleed them again. Drove the car to test them out, and it didn't improve. We literally changed half the fluid to be sure, bled all four corners, and the pedal was still soft, barely improving.

Ran the second session, came back, and the brakes were 90% gone. Let the car sit after riding down the road to keep some air at them, and they were 100% gone.

Bled them enough that I could brave the ride home, skipped the third session, and headed back.

So, the brake fluid has no air bubbles, and the pedal is still soft as hell.

Did I destroy the master cylinder with 121,000 miles on? Destroy the calipers? What is going on here? I'm at a loss.

I'm going to change the fluid with Castrol SRF today, the Super Blue is too weak for a hard drive on CMP (MUCH harder on brakes than VIR), hopefully the SRF does better... But I'm at a loss of why the brakes are not getting better with bleeding.

Any input is appreciated.


Modified by GO-FIGHT-KILL at 8:30 AM 10/13/2008

Jon D

No signs of obvious leaking anywhere? Fluid level is staying consistent, you just have no pedal?

coolhandluke

iTrader: (2)

What pads are you running? Just curious. With the pedal soft a day later and cooled down, I am having thoughts towards a MC issue.

get RIGHT

I'm thinking it has to be another problem other than the fluid. I have tried to boil superblue out of mine and I couldn't do it.

GO-FIGHT-KILL

No leaks what-so-ever. The fluid is perfect level, all calipers bled properly.

Pads are Cobalt GTS Carbon/Ceramic in the front, and OEM in the rear, both on OEM rotors. They did fine at VIR, I doubt the problem is in the pads/rotors (i.e. The pedal would still at least be firm).

I think it is possible linked to the master cylinder. I just want the car to brake like it did the first run out, for the entire weekend... I'm going to be hitting CMP pretty consistanty from here on, so I don't want this to happen on the same basis of consistancy.

GO-FIGHT-KILL

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by get RIGHT &raquo;</TD></TR><TR><TD CLASS="quote">I'm thinking it has to be another problem other than the fluid. I have tried to boil superblue out of mine and I couldn't do it. </TD></TR></TABLE>

It certainly boiled, when we bled it the first time there was a 1-2" section of air coming from each caliper.

I was driving the car incredibly hard... On the edge of too hard for a 'driven to the track' car. To put bluntly, the only other cars that were faster, were two '09 GTRs. So, I'm sure something mechanically went wrong.

coolhandluke

iTrader: (2)

I really only asked just to clarify for other readers, it didn't sound like they were your problem. I really think you have a mechanical issue with the booster, MC, vacuum leak. I'm guessing at this point but I'm trying to think of all the interrelated parts to the MC.

GO-FIGHT-KILL

Oh I gotcha', I understand what you were saying, I was just clarifying for other readers too.

I'm not sure what could cause progressive decline in pedal pressure other than the master cylinder going out... It still grips a bit, the last master cylinder I had go out just plain went out.

Bradstard

I have run CMP many times during the summer. I also push my car VERY hard on the track. I have never been able to boil ATE Super Blue at CMP. Hell, I ran Autozone brand DOT3 for about year at CMP and it held up fine. I doubt the problem is your fluid.

Has anything changed recently on the car? New SS lines? New calipers? Anything?

John Z

if you bled them right im going to go with a failing master. what brake lines are you running how do they look?

Dave-ROR

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bradstard &raquo;</TD></TR><TR><TD CLASS="quote">I have run CMP many times during the summer. I also push my car VERY hard on the track. I have never been able to boil ATE Super Blue at CMP. Hell, I ran Autozone brand DOT3 for about year at CMP and it held up fine. I doubt the problem is your fluid.

Has anything changed recently on the car? New SS lines? New calipers? Anything?</TD></TR></TABLE>

You brake like I do thought right? IE, hard on the brakes, then off of them? Some drivers will drag the brakes, which is when you can more easily boil fluid, I know I did my first few track events.

Did you push the pedal to the floor when bleeding? You aren't supposed to, I have for years and haven't had problems, but I've also switched out master brake cylinders for cars that have broken a seal doing so..

GO-FIGHT-KILL

Ah, so what's the proper bleeding technique? The pedal was going to the floor during bleeding, that may be the problem.

I wasn't braking too draggy, on hard/off soft, no dragging really.

I'm leaning with master cylinder at this point.

jgirard

Jordan when bleeding you pump it, but don't push the pedal all the way to the floor cause it could blow out the seal in the MC

walker111

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bradstard &raquo;</TD></TR><TR><TD CLASS="quote">I have run CMP many times during the summer. I also push my car VERY hard on the track. I have never been able to boil ATE Super Blue at CMP. Hell, I ran Autozone brand DOT3 for about year at CMP and it held up fine. I doubt the problem is your fluid.

Has anything changed recently on the car? New SS lines? New calipers? Anything?</TD></TR></TABLE>

x2!

The problem is not the fluid. I have the exact same setup as you and I'm sure I push my car just as hard if not more.

[freak] the old fashion bleeding mechanism, in a pinch it will work but when you want it done right.....use vacuum. Snap-on makes a vacuum bleeder that I use everytime. Takes 15 minutes to do the whole car and you CAN'T [freak] it up. Make sure your "performance" brake fluid is fresh, buy more than enough, and suck away.

I would look into MC problems way before I doubt superblue. Not saying it cant be boiled......just saying i dont think you are.

POLYGLYCOL ETHER BASED FLUIDS
Fluids containing Poly glycol ethers are regarded as DOT 3, 4, and DOT 5.1. These type fluids are hydroscopic meaning they have an ability to mix with water and still perform adequately. However, water will drastically reduce the boiling point of fluid. In a passenger car this is not an issue. In a racecar it is a major issue because as the boiling point decreases the performance ability of the fluid also decreases.

Poly glycol type fluids are 2 times less compressible than silicone type fluids, even when heated. Less compressibility of brake fluid will increase pedal feel. Changing fluid on a regular basis will greatly increase the performance of the brake system.

jm01dc

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jgirard &raquo;</TD></TR><TR><TD CLASS="quote">Jordan when bleeding you pump it, but don't push the pedal all the way to the floor cause it could blow out the seal in the MC</TD></TR></TABLE>

Hmmm, not sure about this, don't know how an ITR would be different .. but correct me if I'm wrong, if you're using the helper system...


The bleeder valve/bolt should be closed, the person inside the car should be pushing down on the brake all the way, right before the pedal hits the floor, you're going to open the valve slightly. Pedal goes all the way to the floor.

You then close the valve, lift up on the brake pedal, and repeat the process.

Bbasso

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GO-FIGHT-KILL &raquo;</TD></TR><TR><TD CLASS="quote">the Super Blue is too weak for a hard drive on CMP</TD></TR></TABLE>

Who told you that? (BS on them)
as stated before it's not the fluid problem is elsewhere.
Sounds like brake pad fade to me.
Which pads did use?

walker111

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bbasso &raquo;</TD></TR><TR><TD CLASS="quote">

Who told you that? (BS on them)
as stated before it's not the fluid problem is elsewhere.
Sounds like brake pad fade to me.
Which pads did use?</TD></TR></TABLE>

He said gtsports, I know you, andy, brad, and others use different but I dont get fade from them.

get RIGHT

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by walker111 &raquo;</TD></TR><TR><TD CLASS="quote">

He said gtsports, I know you, andy, brad, and others use different but I dont get fade from them.</TD></TR></TABLE>
Me niether.

Bbasso

two things...
bad set of pads.
or
not driving correctly or over driving the pads. GT Sports are good but only a mid- level pad.

walker111

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bbasso &raquo;</TD></TR><TR><TD CLASS="quote">two things...
bad set of pads.
or
not driving correctly or over driving the pads. GT Sports are good but only a mid- level pad.
</TD></TR></TABLE>

I think for occasional track weekends they're for any driver.

GO-FIGHT-KILL

Thanks for all the input guys.

I'm confused as to how when we bled the brakes the first time after they were first 'boiled', a large air bubble came out of each caliper... How did that happen if they didn't boil?

I'm so confused as to what's causing this problem, I'm not sure where to start as far as resolving it.

Dave-ROR

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jm01dc &raquo;</TD></TR><TR><TD CLASS="quote">

Hmmm, not sure about this, don't know how an ITR would be different .. but correct me if I'm wrong, if you're using the helper system...


The bleeder valve/bolt should be closed, the person inside the car should be pushing down on the brake all the way, right before the pedal hits the floor, you're going to open the valve slightly. Pedal goes all the way to the floor.

You then close the valve, lift up on the brake pedal, and repeat the process.
</TD></TR></TABLE>

Put something (a small piece of 2x4 for example) under the pedal to prevent the seals from being cut/ruptured by moving too far into the cylinder.

Dave-ROR

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GO-FIGHT-KILL &raquo;</TD></TR><TR><TD CLASS="quote">Thanks for all the input guys.

I'm confused as to how when we bled the brakes the first time after they were first 'boiled', a large air bubble came out of each caliper... How did that happen if they didn't boil?

I'm so confused as to what's causing this problem, I'm not sure where to start as far as resolving it.</TD></TR></TABLE>

It's possible you boiled the fluid, how fresh was the fluid? However, Super Blue is a perfectly fine fluid for CMP, even for much larger, heavier and faster cars than an ITR. I believe that's what craig's M3 had on it, and it had two drivers beating on it with zero fade.

It could also have been bleed incorrectly last time and the problem didn't present itself until the fluid heated up.

I wouldn't question using ATE Super Blue, but the main concern I have is how in the hell you boiled fluid on all four calipers.....

GO-FIGHT-KILL

It was only the front calipers that I got any air out of initially... From that point on, no air came out. The fluid is pretty fresh, it was put in right before Type-R EXPO.

I will say, the past dozen times I've bled the brakes, the pedal has gone to the floor. That may have destroyed the master cylinder seal?

Ever since I went to ATE Super Blue, the pedal has felt as if there is no pedal pressure until 25% in, then it started gripping well... I wonder if my master cylinder seal has just been going bad since then.

How far should the pedal be depressed when manual bleeding is taking place? 80%?


Modified by GO-FIGHT-KILL at 11:48 AM 10/13/2008

get RIGHT

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GO-FIGHT-KILL &raquo;</TD></TR><TR><TD CLASS="quote">

Ever since I went to ATE Super Blue, the pedal has felt as if there is no pedal pressure until 25% in, then it started gripping well... I wonder if my master cylinder seal has just been going bad since then.

How far should the pedal be depressed when manual bleeding is taking place? 80%?


</TD></TR></TABLE>
I'm leaning towards the MC at this point.

I never press more than 50%. My block of wood stops me at that point.