0Todd TCE

Only difference are the flare fittings on the hard lines.

JRitt@essex

I agree with everything Bill Dearborn said above. Listen to the man! It's something to do with the pad wear sensor, and the wheel weight is likely making contact with the caliper body. Check the caliper for witness marks. They shouldn't be making contact if you're on stock wheels, but if the adhesive fails and they start to sag, they could easily grab the caliper. Put a nice piece of Gorilla Tape over the wheel weights to make sure they don't drop down and hit the caliper.

JRitt@essex

C5 and C6 share master cylinders across the range and trim levels. With our Essex Designed AP Racing Brake Kits, the difference comes down to the brake lines. One chassis has a convex brake line fitting at the hard line attachment point, the other has a concave fitting. That's the reason for the different part numbers. Otherwise our C5 and C6 kits are the same. That may be different for other manufacturers though, so make sure you check with the specific manufacturer before swapping to a new chassis.

KNSBrakes

Stoptech kits have different piston sizes between base and Z06 on C5/C6 base cars and they observe the brake line difference as well.

mr.beachcomber

If you are using the correct master cylinder for your '68, you should have two bleeder screws - one to bleed the front and the back reservoirs. When I was racing my '72 B Production Vette, I found that there would be a little air within the master cylinder even if I bench bled the unit first before installing. You might try re-bleeding the master cylinder as installed. (Double check that you haven't installed a master cylinder for power brakes on your manual system. The difference between the two is the internal bore size for the piston. The one for power brakes is larger and will give a mushy pedal on a manual system.)

You mentioned that you've gone through two quarts of brake fluid. I'm guessing this is from constant bleeding to get a firm pedal. It wouldn't hurt to check and see if you're weeping brake fluid around any of the fittings for the new calipers/master cylinder. It wouldn't hurt to check the rest of the steel/rubber lines/fittings also.

Hope this helps!

rad63

I am have 2008 C6 Z51, and I autocross it extensively. I run SCCA A street class, so car is basically stock.

I believe I experience "ice mode" from time to time, but not really sure: my brake pedal becomes rock hard and car doesn't stop. It is not consistent and never happens on the street, so no real way to reproduce.

Another theory is that after a lot of steering front wheels overheat together with brakes.

On my last run I failed to stop at straight line after finish, so I think that something is definitely not right.

I have stock Z51 rotors (probably original from 2008, 35k miles on them)
Stock Z51 brake pads (all changed 6 months ago)
Endless RF-650 brake fluid (changed 3 month ago)
Bridgestone RE71 tires (new)

urslooow

tony 63 vette

Hello my name is Tony I have a c7 Z51 10k miles built 10/15 chatter comes and goes daily basis most noticible @ 40 mph light pedal any ideas???

rad63

I *think* I also feel ABS kicking in when this happens. And never experience hard pedal on highway. So is it possible that brake booster only misbehaves at autocross?

urslooow

Poor-sha

That could also be the pads overheating. Do you see any splotchs or what looks like smearing of pad material on the rotors? You should see an even layer of pad material.

romandian

so i have been thinking, why are there no titanium pistons (or are threre)? ti is less conductive than stainless and stronger than aluminum. also i have come accross phenolic pistons. how good of an idea is that and why are they not more popular? phenolic is one of the hardest plastics but with todays abs i wouldnt trust it.

badhabit_wb

0Todd TCE

Ti heat shields would seem to be equally effective for far less money. Given they go on the back of the pad plate the insulation value runs the length of the entire pad.

I stock them for all the Wilwood calipers and have them for the rear of the C5/6 now just have not done fronts.

JRitt@essex

romandian,
Your conclusion is a logical one!

The current batch of elite-level racing calipers all have titanium pistons. Below are some shots of the AP Racing Radi-CAL calipers that just won the season championship in NASCAR Sprint Cup, along with some F1 calipers. As you noted, titanium does an excellent job of keeping heat out of fluid. At the highest level, weight savings is what makes titanium so desirable. It is incredibly lightweight, and the clear choice when cost is not a concern.

That said, it's also really expensive! Stainless steel is almost as good as titanium at keeping heat out of the fluid, except at a much lower cost. Stainless steel pistons were used in the Radi-CAL calipers that have won Le Mans on the Porsche 911 RSR and on the Corvette C7R, and we use stainless pistons on all of our Radi-CAL calipers that are available for corvettes. Phenolic pistons have been used in many places of the years, but haven't proven as effective, durable, etc under race conditions as stainless or titanium.

Below are some images of the titanium pistons found in AP Racing Radi-CAL calipers used in Formula 1, a NASCAR Cup, and GT3.

Formula 1



Sportscar Caliper




NASCAR Cup rear...yes, that caliper weighs 2.5 lbs., partially due to the titanium!



In my palm...tiny little guy...



When I was digging through my files I found this pic...obviously I was telling someone what I thought about aluminum pistons for track use along the way. Friends don't let friends track aluminum pistons! :p




Here are the ventilated stainless steel pistons we use in all of our Essex Designed AP Racing Radi-CAL Competition Brake Kits for Corvettes. They are incredibly effective at preventing brake fluid from boiling.



Here's what they look like on the back side. They have a domed back to add stiffness, and an anti-knockback spring attached.



Hopefully that gives you an idea of some other solutions that are being employed. If you want to see more pics of the Radi-CALs (they are automotive sculpture), check out our recent post about SEMA 2018 on the Essex Blog.

KNSBrakes

When you have all the moneys - you get titanium!

romandian

thanks folks. i was not avare of titanium pistons actually being used. that vid is interesting (i almost died watching it) but the conclusion is wrong imo. you would not make the titanium piston like the phenolic, there is no need for that "puck" type construction. a titanium piston of regular shape obviously has a smaller cross section and will conduct less heat.

WhiteRocket

Looking for suggestions.
I have a 17 Z51 that I will be doing track days and HPDE events. Looking for a low dust pad that is suitable for both Track and street.

I will not run powerstops as they turn my rotors brown/rust color. Been there, Done that, Dont want them.

Please advise.

strano@stranoparts.com

you can't have it all. Pads are going to work on a track or not going to be clean. Pads they're going to be clean are not going to work on a track. And there are precious few pads that can even claim to do both decently.

Notepad can work as well on the street as it does on the racetrack or vice versa. that said I have some pad options that may work for you. I test a lot of different things, and I did find a pad a couple years ago that I tracked for 7 days both on Hoosiers and on Street tires, I autocrossed on and I daily drove the car on. And that set of pads on my c606 actually lasted almost a year.

WhiteRocket

I figured that but had to ask.
Which pads are you describing above?