First session brakes felt unusual after 10-15 minutes, then got a brake failure on dash. Zero brake petal coming into pits. I was not driving harder than I have in past, but this is the 5 track day on this Motul 660 fluid. No street driving at all.

I think I read you have to go to dealership to reset computer??? Any ideas? After cooling down a little the petal is back, but dash says speed is limited to 43 miles per hour.

ideas? Plan to disconnect battery, flush fluid, but not sure if boiling fluid was the problem.

 

Z51 brakes or regular? Pad type?

Id do exactly what you plan which is drain the fluid. Id inspect the pads to see if they can tell you anything.

Make sure no stuck pistons and seals are intact.

Do you have brake ducts installed and consider titanium shims and Castrol SRF

 

Stock C8

code P25A2

 

Youve got smaller brakes with 5 track days on the fluid. Id do exactly what you're planning and get a Castrol srf in there. You may have to change out the fluid slot more often until you upgrade the brakes is tracking is going to be a regular hobby

 

To reset the brake warning, with foot off the brake pedal, push the start button and hold it in for 30 seconds or so. This effectively turns on all electrical systems without running the motor. Keeping the start button pressed, push down hard on the brake pedal and keep it down until the clicking stops.
Above is the procedure I followed when I tripped brake warning after replacing the pads.

 

I tried this procedure, but still have the problem.

I believe I read somewhere on this forum months ago that someone had same problem at the track . Codes have to be reset at dealership or a special scanning tool is required.

I should have bled the brakes… stupid me. I think there was a tiny bit of fluid overheating with bubbles even though I was not as hard on the brakes as I have been in the past, and the car went into nanny mode. However, I had no petal at all when I immediately came into pits, petal went to floor. so if it’s not nanny mode, something broke.

Driving the car now the petal feels completely different and I can here a clicking noise coming from the brake fluid reservoir area when stopped at the red light and stepping on the petal. Lift off petal clicking stops.

I spoke to tech on phone at dealership. He thought maybe I blew a fuse to the brake module ???? Just a guess. He did not know where fuse was located….

 

I had my 22 C8 since last November so I am a newbie to this car. I triggered brake warning when I replaced my brake pads and brake feel and vehicle speed being limited to 43 MPH you are describing is exactly what I experienced although the condition that caused it is totally different.
In my case, because I forgot to disconnect the battery when I started on the rear brake, somehow, car sensed pad (or piston) movement although the brake pedal was stationary causing brake warning and triggering the braking system to go into limp home mode and limiting the vehicle speed for safety reason. I drove like this for 60 miles to get home from my friend's garage - NOT FUN!
Could it be that when your brake fluid boiled, brake pedal movement and pad (or caliper piston) movement did not correlate from ECM (PCM or whatever it's called) triggering brake malfunction code and going into limp home mode? My understanding of "P" code is of "powertrain". Could this be the code indicating fuel delivery is being curtailed to limit speed?
For what it's worth, it took me 5 - 6 tries to successfully reset the brake. To reset the brake, last try I pushed the brake pedal really hard as engine start was in push position after going into "run" position without the motor running.
Nothing to lose. Try the reset procedure a couple more times.
Good luck!

 

I also had to reset the brake system once. I did it using the above procedure, however, I did not keep the start button pushed. After all the electrical systems were on, I released the start button, then pushed the brake pedal as hard as I could and kept it that way until the clicking stopped. That reset the brake system. A good OBD2 device can reset the check engine/engine malfunction light.
YMMV

 

Fixed it!!

the trick was TO NOT HOLD start key in while pushing on brake petal. All warnings went away, but the engine icon light is on. But I’m back to warp speed!

I’ll bleed brakes tomorrow and I’m back on the track.

thanks so much, Sean

 

Glad to hear you got it reset. 300 miles with 43 mph restriction and sketchy brakes would have been hell.
Next time, I’ll try both - with switch pushed and without.

 

I owe you a beer!

 

you are on!

 

Well after 3 laps into the second session today the Brake System Failure came back. First session had no issues. We bled all the brakes first thing in the morning. So, boiling fluid was not the problem. .

Instead of being limited to 43MPH like yesterday, today the warning said speed was limited to 62MPH. I cleared the BRAKE SYSTEM FAILURE again and now have a Service ESC and Service Brake Assist, and the engine icon and traction icon warning light is on, but the speed was not limited.

Tomorrow I’m going to remove the calipers and see if I see anything obviously wrong. I’ll be taking it to the dealership later, but I have no confidence they know what is wrong.

 

Sorry you are having the problem, Hopefully it is not something serious...

 

Like i mentioned make sure you inspect the seals. 5 track days on non z51 brakes and boiled fluid and id be surprised if the seals are intact. When you switch to srf consider bleeding extensively. Id push two liters through.

 

Motul 660 is good fluid, the only thing switching to SRF is going to do is get more peace of mind that all the stock fluid is out of the system and you get the system bled properly. I think this sounds more like an issue of air in the system than a fluid issue.

I run Motul 660 exclusively in my track C8.

 

I don’t see how air could have been introduced into the system unless you are considering air bubbles from possible boiling of the fluid. In previous track events I’ve have been much more aggressive with the brakes with no problems of the Brake System/Computer. And as I said, we completely bled the brakes Sunday morning.

Today I’ll be looking for a sticking piston on the calipers or something along those lines that could generate heat. If there is nothing apparently wrong at the calipers the problem must be within the system.

I’ll keep everyone posted.

This forum is great for the knowledge available here. The trick to clear the Brake System of the 43mph limited speed really saved my *** and hours of time plus arranging a 200 mile ride home from the dealership we’re I would have had to leave the car. !!

 

Is it possible the emergency brake activated when the Brake System Failure kicked in? The pads look very close to the rotor and worn down.

It appears the emergency brake pads are very close to the rotor and worn.

 

Well as expected the idiots at the dealership said my problems were because I was not using the GM brake fluid in the car, which was designed for the corvette. They had never heard of Motul or SFR brake fluid.

They could not explain why a different fluid that I have been using for 8 months with no problem was now causing brake system failure.

My parking brake pads were worn. They said the parking brake engages when the system senses a problem. What?? so I can drive the car at a maximum speed of 43 (Saturday) and 62MPH (Sunday) per the display, while the parking brake is on? I don’t think so.

Their solution was to replace the rotors and bleed the brakes with OEM fluid. Also, since I had changed out the sway bars to larger after market sway bars, I had modified the car and the braking had changed and therefore not under warranty.

Idiots

 

Parking brakes engaged as the car triggered 43 mph max speed after sensing brake problem?! I agree these cars are far more smarter than that.
Larger sway bars affected braking system and voids warranty?! How ignorant can one get?
I hate having to deal with dealership service because of level of intelligent dialog expected. People making stuff up just kills me…
I hope there are other Chevy dealers you can turn to if warranty becomes an issue.