On track brake failure, 2012 ZO6
08-16-2014, 11:13 PM
#42
Racer
Thread Starter
Probably the best point I can emphasize is my issue seemed to be the bleeder screws leaking. I do think that may be the weak point of the OEM calipers. How hard is it to close a bleeder yet these leaked at my third track visit, and highest speed.
The OEM calipers are very unimpressive once you take them off and compare them to the AP's, and others I'm sure.
Clunky heavy, stupid flimsy pad bracket system etc. Did I say heavy?
Wow, big difference.
The pad install on the AP's is so incredibly nice. I've had Brembo's before, thought those were nice for pad install but these are so easy.
I have since purchased an inch/lb torque wrench. I will admit, it seems like very modest pressure to set the bleeders to specs. The AP's are 150 "/lb vs the factory bleeder setting of I think 103 or 105 "/lb.
Either way, it would not be hard to overdo it and the factory calipers may require some caution here. The AP's are obviously built to take a lot more bleeder torque (which still isn't much).
One other point. I got the Spiegler brake lines with this kit. They use a banjo fitting to attach to the caliper, copper washers etc.
The bolt that goes into, or through, the banjo fitting into the caliper, has a much different length than the OEM bolt. Shorter by a lot.
Point is, if I had not gotten the stainless lines with the kit and opted to just bolt the factory rubber brake lines to the AP calipers, no way would they work. The factory bolt was obviously too long and while it would have screwed in, it would have impacted the back of what looks like a center piston.
If you upgrade calipers, you need to get a bolt that attaches the brake line to the caliper that fits your NEW caliper, in length.
The OEM calipers are very unimpressive once you take them off and compare them to the AP's, and others I'm sure.
Clunky heavy, stupid flimsy pad bracket system etc. Did I say heavy?
Wow, big difference.
The pad install on the AP's is so incredibly nice. I've had Brembo's before, thought those were nice for pad install but these are so easy.
I have since purchased an inch/lb torque wrench. I will admit, it seems like very modest pressure to set the bleeders to specs. The AP's are 150 "/lb vs the factory bleeder setting of I think 103 or 105 "/lb.
Either way, it would not be hard to overdo it and the factory calipers may require some caution here. The AP's are obviously built to take a lot more bleeder torque (which still isn't much).
One other point. I got the Spiegler brake lines with this kit. They use a banjo fitting to attach to the caliper, copper washers etc.
The bolt that goes into, or through, the banjo fitting into the caliper, has a much different length than the OEM bolt. Shorter by a lot.
Point is, if I had not gotten the stainless lines with the kit and opted to just bolt the factory rubber brake lines to the AP calipers, no way would they work. The factory bolt was obviously too long and while it would have screwed in, it would have impacted the back of what looks like a center piston.
If you upgrade calipers, you need to get a bolt that attaches the brake line to the caliper that fits your NEW caliper, in length.
08-18-2014, 08:38 AM
#43
Supporting Vendor
Thanks for the purchase 12zo. I'm glad the install went smoothly. Please let us know how they did at the Glen!
On the line routing, we don't put extra length on the lines. They're roughly the same length as stock. Clocking them at 11 or 1, depending on which way you look at it, seems to work well in most cases. Line routing is tough. The issue is that if you put too much length on them, you run the risk of them rubbing a wheel, etc. If they're too short, then you have too much tension on them when the wheel is turned to lock. Typically your car is never going to be at full steering lock and full suspension droop. With our setup, that seems to be the only time you'd have any real tension on the line.
It sounds odd, but on C6 and C7 Corvettes, the line install is actually one of the tougher bits of the overall install. It's tough to get a wrench cleanly on at the hard line attachment point, which gives some people a headache.
On the line routing, we don't put extra length on the lines. They're roughly the same length as stock. Clocking them at 11 or 1, depending on which way you look at it, seems to work well in most cases. Line routing is tough. The issue is that if you put too much length on them, you run the risk of them rubbing a wheel, etc. If they're too short, then you have too much tension on them when the wheel is turned to lock. Typically your car is never going to be at full steering lock and full suspension droop. With our setup, that seems to be the only time you'd have any real tension on the line.
It sounds odd, but on C6 and C7 Corvettes, the line install is actually one of the tougher bits of the overall install. It's tough to get a wrench cleanly on at the hard line attachment point, which gives some people a headache.
Last edited by JRitt@essex; 08-18-2014 at 08:47 AM. Reason: added info
08-18-2014, 08:56 AM
#44
Supporting Vendor
Yes, you can run OEM-style C6 Z06 discs with our calipers with our six piston Endurance Kits, although we don't sell the kit components separately (the kit components are all designed to work together for optimum results). If you wanted to run that type of disc for light-duty use, it could definitely cut down on your overall long-term running costs.
In order to run a one-piece OEM-style C6 Z06 disc, you have to shim the caliper roughly 1mm. I have a note about it on our website. Scroll down about 3/4 of the way on this page and it's titled:
Using OEM-Style C6 Z06 Discs with our System
It looks like this:
On our smaller Sprint Kit, which features a 325x32mm disc, most OEM-style discs bolt right up without any shims, etc. (I say most, because OEM-style discs tend to vary a bit in dimension. There will likely be exceptions that don't work. For our measurement purposes, we typically use Centric 120.xxxxx OEM-replacement discs).
Last edited by JRitt@essex; 08-18-2014 at 09:01 AM. Reason: added additional info
08-18-2014, 10:40 PM
#46
Racer
Thread Starter
Thanks for the purchase 12zo. I'm glad the install went smoothly. Please let us know how they did at the Glen!
On the line routing, we don't put extra length on the lines. They're roughly the same length as stock. Clocking them at 11 or 1, depending on which way you look at it, seems to work well in most cases. Line routing is tough. The issue is that if you put too much length on them, you run the risk of them rubbing a wheel, etc. If they're too short, then you have too much tension on them when the wheel is turned to lock. Typically your car is never going to be at full steering lock and full suspension droop. With our setup, that seems to be the only time you'd have any real tension on the line.
It sounds odd, but on C6 and C7 Corvettes, the line install is actually one of the tougher bits of the overall install. It's tough to get a wrench cleanly on at the hard line attachment point, which gives some people a headache.
On the line routing, we don't put extra length on the lines. They're roughly the same length as stock. Clocking them at 11 or 1, depending on which way you look at it, seems to work well in most cases. Line routing is tough. The issue is that if you put too much length on them, you run the risk of them rubbing a wheel, etc. If they're too short, then you have too much tension on them when the wheel is turned to lock. Typically your car is never going to be at full steering lock and full suspension droop. With our setup, that seems to be the only time you'd have any real tension on the line.
It sounds odd, but on C6 and C7 Corvettes, the line install is actually one of the tougher bits of the overall install. It's tough to get a wrench cleanly on at the hard line attachment point, which gives some people a headache.
Overall, a very nice install.
My first day back at Watkins Glen following the pedal to the floor deal here one month ago was interesting.
The front brakes are very impressive. Super smooth feel to the Ferodo pads, almost a bit softer a bite than expected but so progressive. Your calipers with those pads is really a huge amount of brake force that just keeps digging in as you go deeper into the pedal and brake zone. Nice.
Back brakes, not so good. I still have my factory calipers etc on the back. DBA and Carbotech. Those calipers had not leaked before. It was just the fronts.
First session out I had a little fluid seepage now this time from those rears. Had not seen that before. Thought I'd be parking her again but ran a second session, double pumping the pedal and expecting some hint of a soft pedal. Never happened. The rears never leaked again.
The OEM calipers are just weird. Without getting too long winded, I've lost faith in them now too and will be ordering your rear kit. Between the fluid leak session one and then no leak, the slight wiggle out of the rear at threshold braking and my prior experience, I'm done with all the factory calipers. I want rears to match the front.
No, the leak is not residual fluid from the bleeder valve. I use a Moroso trick and put a pipe cleaner in the bleeder after bleeding so there simply is no fluid to then come out of the bleeder. It must be from that first "cold" session where the caliper and bleeder metals are not mating.
The rear wiggle could be for a variety of reasons but I'm not going to have calipers that weep on my car.
Whatever, I want AP brakes on all four corners.
Someone please buy my DBA 5000 front rotors and Carbotech 12 pads for sale. My rear DBA 4000 and Carbotech 10 pads will be for sale soon.
They are good rotors and pads and lightly used. They are in the classified.
My issue is the factory calipers. You can't stand on the brakes at Watkins Glen with OEM calipers. Not the first session, not all day.
The AP's seem like they are just all to happy to have you brake harder and harder and I keep saying "Really? There's more brake?"
08-20-2014, 10:35 PM
#47
Racer
Thread Starter
Rear 5040 Essex AP Endurance ordered today.
Thanks Jeff at Essex for a ton of info.
My entire DBA 5000/4000 and Carbotech XP 12/10 setup is for sale over on the racing classified page.
http://forums.corvetteforum.com/auto...h-pads-fs.html
I will pull the OEM calipers etc off next Tuesday and bolt on the AP package.
Fronts for sale there now, rears available next week.
Very low time on this equipment folks.
Thanks Jeff at Essex for a ton of info.
My entire DBA 5000/4000 and Carbotech XP 12/10 setup is for sale over on the racing classified page.
http://forums.corvetteforum.com/auto...h-pads-fs.html
I will pull the OEM calipers etc off next Tuesday and bolt on the AP package.
Fronts for sale there now, rears available next week.
Very low time on this equipment folks.
Last edited by 12zo; 08-21-2014 at 09:49 AM. Reason: Link added
09-04-2014, 11:31 PM
#48
Racer
Thread Starter
Brake issue should be resolved. Front and rear's replaced now with Essex AP Endurance kits.
The car has a very different look now and I like it, but beyond that I know I have no more braking issues.
The car has a very different look now and I like it, but beyond that I know I have no more braking issues.
04-03-2019, 12:52 PM
#50
Very informative thread even though old. I just tracked my c6 z06 for the first time at NJMP and had the exact same issue 12zo had. I have 1 faulty bleeder (LF outer bleeder screw) that I believe was leaking on track after heavy breaking. I lost my brakes my first session and had to come in early. I saw dry brake fluid that looks to be coming down from that bleeder. I loosened and retightened the bleeder. When the brakes cooled, the pedal firmed up again. I reduced my end straight speed in order to reduce heat generation on brakes since its the only spot in NJMP with hard breaking. Didn´t have an issue after. Believe that LF bleeder isn´t seating well.
I did a full rebleed after the event and noticed only that bleeder seems to be not smooth when screwing and unscrewing the bleeder. Seems to move around in threads more. I plan to replace the bleeder and see if threads were bad.
My second thought was I didn´t remove all the old DOT3 fluid when reflushing with Castrol SRF. I had a hard time removing the old fluid in the bottom of master cylinder since there is little access. Therefore the old fluid in system could have boiled causing the soft pedal and resolving after the fluid cooled. The second time I rebleed after the track, I got a 100 cc syringe with small tubing to remove that extra fluid at bottom. I believe this should help a lot.
I think I need the AP racing or Stoptech kits if I want to push the car harder and have confidence. Nothing is worse than not having confidence in your brakes when tracking. Had to resolve similar issues in my s2000 track car before feeling great with it.
I did a full rebleed after the event and noticed only that bleeder seems to be not smooth when screwing and unscrewing the bleeder. Seems to move around in threads more. I plan to replace the bleeder and see if threads were bad.
My second thought was I didn´t remove all the old DOT3 fluid when reflushing with Castrol SRF. I had a hard time removing the old fluid in the bottom of master cylinder since there is little access. Therefore the old fluid in system could have boiled causing the soft pedal and resolving after the fluid cooled. The second time I rebleed after the track, I got a 100 cc syringe with small tubing to remove that extra fluid at bottom. I believe this should help a lot.
I think I need the AP racing or Stoptech kits if I want to push the car harder and have confidence. Nothing is worse than not having confidence in your brakes when tracking. Had to resolve similar issues in my s2000 track car before feeling great with it.
04-03-2019, 01:48 PM
#51
Supporting Vendor
Very informative thread even though old. I just tracked my c6 z06 for the first time at NJMP and had the exact same issue 12zo had. I have 1 faulty bleeder (LF outer bleeder screw) that I believe was leaking on track after heavy breaking. I lost my brakes my first session and had to come in early. I saw dry brake fluid that looks to be coming down from that bleeder. I loosened and retightened the bleeder. When the brakes cooled, the pedal firmed up again. I reduced my end straight speed in order to reduce heat generation on brakes since its the only spot in NJMP with hard breaking. Didn´t have an issue after. Believe that LF bleeder isn´t seating well.
I did a full rebleed after the event and noticed only that bleeder seems to be not smooth when screwing and unscrewing the bleeder. Seems to move around in threads more. I plan to replace the bleeder and see if threads were bad.
My second thought was I didn´t remove all the old DOT3 fluid when reflushing with Castrol SRF. I had a hard time removing the old fluid in the bottom of master cylinder since there is little access. Therefore the old fluid in system could have boiled causing the soft pedal and resolving after the fluid cooled. The second time I rebleed after the track, I got a 100 cc syringe with small tubing to remove that extra fluid at bottom. I believe this should help a lot.
I think I need the AP racing or Stoptech kits if I want to push the car harder and have confidence. Nothing is worse than not having confidence in your brakes when tracking. Had to resolve similar issues in my s2000 track car before feeling great with it.
I did a full rebleed after the event and noticed only that bleeder seems to be not smooth when screwing and unscrewing the bleeder. Seems to move around in threads more. I plan to replace the bleeder and see if threads were bad.
My second thought was I didn´t remove all the old DOT3 fluid when reflushing with Castrol SRF. I had a hard time removing the old fluid in the bottom of master cylinder since there is little access. Therefore the old fluid in system could have boiled causing the soft pedal and resolving after the fluid cooled. The second time I rebleed after the track, I got a 100 cc syringe with small tubing to remove that extra fluid at bottom. I believe this should help a lot.
I think I need the AP racing or Stoptech kits if I want to push the car harder and have confidence. Nothing is worse than not having confidence in your brakes when tracking. Had to resolve similar issues in my s2000 track car before feeling great with it.
But we have supported many track guys with one piece pads and good blank rotors and while it has warts the brakes are serviceable on track. If the pad wear starts to get up there than yes the BBK will help.
I do not get large amounts of fluid boiling feedback on the C6Z/GS brakes and users try even lesser fluids.
The worst issues seem to stem from the padlet design and the pins - and the oddly vented factory rotors that are drilled.
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mikeCsix (04-03-2019)
04-03-2019, 01:59 PM
#52
Melting Slicks
Member Since: Jul 2010
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The drilled rotors are completely useless on track. With factory pads, I can fill the holes with dust in just a few laps, plus the holes reduce effective surface area of the disk. For "normal" rotors, DBA 4000 seems to work well. The AP racing rotors look outstanding...
04-03-2019, 02:01 PM
#53
Supporting Vendor
The drilled rotors are completely useless on track. With factory pads, I can fill the holes with dust in just a few laps, plus the holes reduce effective surface area of the disk. For "normal" rotors, DBA 4000 seems to work well. The AP racing rotors look outstanding...
04-03-2019, 06:55 PM
#54
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Very informative thread even though old. I just tracked my c6 z06 for the first time at NJMP and had the exact same issue 12zo had. I have 1 faulty bleeder (LF outer bleeder screw) that I believe was leaking on track after heavy breaking. I lost my brakes my first session and had to come in early. I saw dry brake fluid that looks to be coming down from that bleeder. I loosened and retightened the bleeder. When the brakes cooled, the pedal firmed up again. I reduced my end straight speed in order to reduce heat generation on brakes since its the only spot in NJMP with hard breaking. Didn´t have an issue after. Believe that LF bleeder isn´t seating well.
I did a full rebleed after the event and noticed only that bleeder seems to be not smooth when screwing and unscrewing the bleeder. Seems to move around in threads more. I plan to replace the bleeder and see if threads were bad.
My second thought was I didn´t remove all the old DOT3 fluid when reflushing with Castrol SRF. I had a hard time removing the old fluid in the bottom of master cylinder since there is little access. Therefore the old fluid in system could have boiled causing the soft pedal and resolving after the fluid cooled. The second time I rebleed after the track, I got a 100 cc syringe with small tubing to remove that extra fluid at bottom. I believe this should help a lot.
I think I need the AP racing or Stoptech kits if I want to push the car harder and have confidence. Nothing is worse than not having confidence in your brakes when tracking. Had to resolve similar issues in my s2000 track car before feeling great with it.
I did a full rebleed after the event and noticed only that bleeder seems to be not smooth when screwing and unscrewing the bleeder. Seems to move around in threads more. I plan to replace the bleeder and see if threads were bad.
My second thought was I didn´t remove all the old DOT3 fluid when reflushing with Castrol SRF. I had a hard time removing the old fluid in the bottom of master cylinder since there is little access. Therefore the old fluid in system could have boiled causing the soft pedal and resolving after the fluid cooled. The second time I rebleed after the track, I got a 100 cc syringe with small tubing to remove that extra fluid at bottom. I believe this should help a lot.
I think I need the AP racing or Stoptech kits if I want to push the car harder and have confidence. Nothing is worse than not having confidence in your brakes when tracking. Had to resolve similar issues in my s2000 track car before feeling great with it.
A good low cost brake system that will make you safer and provide more fun as well.
Bill
04-03-2019, 10:26 PM
#55
Melting Slicks
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I was having lunch between run groups eating with the driver parked next to me in the paddock. We were talking about cars when all of a sudden we heard this sound from his front end. We looked over and his rotor cracked similar to the picture. Fortunately brought a spare with him, and fortunately it happened during lunch and not on the track or driving home.
04-05-2019, 04:08 PM
#56
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When the brake fluid boils one thing to consider is what is happening to the rear brakes. The C6 has dual diagonal braking and GM did issue a recall for 2005 cars in November 2004 that had issues with the rear brake lines being too close to the driver's side exhaust manifold or exhaust pipe. In some cases the lines actually touched the exhaust parts and they had some brake failures due to that. My 08Z didn't have any trouble with the brake line mounting points but I did take some aluminum foil covered duct tape and cover the lines where they went past the converter (very close due to no space). The number of times I lost my brakes in the pits or pit lane when pulling off the track after a session dropped.
Bill
Bill
04-09-2019, 07:36 PM
#57
Racer
I was having lunch between run groups eating with the driver parked next to me in the paddock. We were talking about cars when all of a sudden we heard this sound from his front end. We looked over and his rotor cracked similar to the picture. Fortunately brought a spare with him, and fortunately it happened during lunch and not on the track or driving home.
My first trip to COTA with brand new stock brakes, pads, rotors and Motul RBF; i pretty much destroyed the front brakes in 2 - 25 minute HPDE sessions. The pads just got eaten up so fast i was shocked, but coming down that back straight at 150+ and then standing on the brake pedal before the hairpin is just way too much to ask from a stock setup. I managed to just let out early and take it easy on the brakes the rest of the weekend just to have fun. My front rotors had cobweb cranks everywhere. That's when i decided it was time to upgrade! Coming into T12 and having the pedal go almost to the floor was a bad moment. Not something i want to experience again if i can help it.
Last edited by Premiumspeed; 04-09-2019 at 07:37 PM.
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xene106 (04-11-2019)
04-11-2019, 10:17 PM
#59
I agree with above, but if the threads are damaged on the bleeder and/or caliper it won't allow the bleeder to sit properly on the mating surface in caliper. To form a nice seal. Will still try a new one since it is a cheap fix.
Based on everyone's comments seems replacing the front rotors with DBA 2 pieces would be a smart move since the vane design of stock rotor is crap lol.
Based on everyone's comments seems replacing the front rotors with DBA 2 pieces would be a smart move since the vane design of stock rotor is crap lol.
Last edited by xene106; 04-11-2019 at 10:18 PM.