I finally got the chance to drive my Corvette on the track, prior to going I did all of the logical things to prepare the stock system.

1. I replaced the stock fluids with high temp Dot 4 brake fluid 683 rated from MTI racing.

2. I put in my cooling rings

3. Changed out the pads to Carbotech XP20 all around.

4. Installed Spiegler Stainless lines

I was at Road America and did 2 laps and started hearing a sizzling sound from the brakes, and then noticed the pedal getting soft. I pulled in and looked at my brakes and I had brake fluid coming out of all 4 calipers bleeder valves, of course it wrecked the paint on the calipers.

I was really puzzled so we bled the brakes and used new brake flud, and torqued the bleeders to the factory spec. I went out again and 2 laps later I can hear the sizzling again. I pulled and the same thing was happening the fluid was coming out of the bleeders.

Let me first say I have been driving on a track for 15 years and know how to use my brakes, this was my first time out and I wanted to get to know the car so I was taking it fairly easy. This was at Road America and it is extremely fast but without a doubt this was the craziest thing I have ever seen and extremely dissapointing.

I can't figure out how the fluid would come out the bleeders, and how it possibly got hot enough to boil that high of temp fluid.

 

Weird, the bleeders should never leak when closed.

Did you use the same torque wrench both times? Maybe it is way off?

Was the fluid actually boiling or just coming out of the bleeders from the pressure applied during heavy breaking. The sizzling would happen when it hit hot brake parts.

 

If the pressure is being bled off by the bleeder screws, the boiling point will be lower.

But that is bizarre, especially if you properly torqued the bleeder screws.
S.

 

Sorry to hear that.

 

It was not uncommon for C6 Z06 caliper bleeders to seep at the track.

Didn't think the Brembo calipers would seep.

 

I haven't heard of anybody else having this happen. So disapointing I had to take the car home and bring back my M3.

Even my stock M5 didn't do this at Road America. I don't know what to do now it was literally all four calipers.

 

The bleeders are softer than the calipers. Use new bleeder screws when the brakes are bled
.

 

I just read on a Porsche forum this symptom can happen when the bleeders are over tightened it strips the seal and will leak under pressure.

I have had the same bleeders in my Stoptech's for 10 years and had them bled numerous times with no issues.

 

Sounds like crushed bleeder seals. They may have been overtorqued at the factory. Hope the caliper threads are still OK...

 

The only odd thing is that all four did this... Seems unlikely that all of them were crushed.

 

My dealer just informed me that Brembo has issued a torque revision on their C7 calipers' bleeders. They are now calling for 142 inch/pounds (about 12 foot/lbs) vs. the previous recommendation of 106 inch/lbs (about 9 foot/lbs).

 

Leave it to me to find the problem, I know of another person who this happened to as well. They replaced all four calipers for him as well.

 

Aren't XP20's a bit much for stock tires?

 

I had Pirelli slicks ready to go on the car, but they didn't fit. BTW Cray 18's don't clear the stock calipers even though Cray says they do.

 

CCW's 18" will fit with OE wheels easily, even with Brembo GT 6-piston calipers and 350mm x 34mm Type-3 rotors. See: http://www.ccwheel.com. No spacers required!

However if you install the Brembo GTs in the front, they will not fit with the OE Z51 wheels. For OE Z51 wheels to clear the BBK Brembos, you'll need 6 mm of wheel spacers. Unfortunately this will result in a full loss of the hub-centric wheel to hub connection. A larger wheel spacer with a built in hub-centric will result in the front wheels protruding well beyond the front fenders.

 

Glad to hear you are OK and didn't stuff it into the wall. BTW-Stock C5 Z06 rears will work on all 4 corners.

 

Question: are you running stock rubber? XP20's are a really aggressive pad, especially in the rear.

Max I'd run on stock rubber are XP10's up front and the '8's in the rear.