purchased low mileage '06 in March. after 4-500 miles, brakes begain to fade--would firm up when pumped but fade got worse. Replaced master cylinder(there had been no leaks) Drove about 1200 miles home. Same problem started again. Local mechanic said replacement M.C. faulty(was new, not used or reconditioned). Put in another M.C. Shortly thereafter, same issue but braking gradually declined to almost nothing(pedal to floor). Another mechanic advised that lines not bled properly. After 6 weeks of limited driving fading again.
Has anyone ever had this experience? Suggestions? Help?------thanks

 

Start with the easy and cheap stuff first... sounds like air in the system... Find a new mechanic and have the brakes bleed again...

 

also, if you're tracking air in the lines, find a mechanic who has access to a tech II and can cycle the ABS to ensure that there isn't air in that part of the circuit. I wonder if it's something simple like a bad bleeder screw / hairline crack in the caliper / piston / etc.

When the car is up in the air, does any of the suspension components appear wet with brake fluid? What is the color of the fluid in the master cylinder (I assume it's clean as you have replaced it twice) what about the color of the fluid coming out of the bleeder screws.

 

06 14 year old hoses between the body and caliper Teflon SS braided lines and a good flush and bleed. any where near Alabama? I have the bleeder and can show you how to do the work.

 

thank you for suggestion ---will follow up here as I am in Canada
a friend also suggested a faulty electronic brake control module--your thoughts?

 

thank you for suggestions--I plan to follow up shortly
as I mentioned to jonjoy an aquaintance mentioned possibility of a faulty electronic brake control module--your thoughts on this?
how does onr check this out
thanks

 

yes--inquiring re another mechanic
any thoughts re faulty electronic brake control module?

 

If it had a faulty brake control mod. I think you would throw a code at least if not the brakes not work at all

 

Brake fade is when the pads become hot, and you start to loose the initial grip that the pads once had.

With you having to play the pump up game and the brake system bleed correctly, your loosing fluid and air is getting back into the lines isntead.

As for ABS system, could be the problem, if the valve are so corrosive that it took out the seals.


Myself, would start checking the system for a fluid leak to start with.
While at the calibers, would double check to make sure that they are free floating on their guide pins, hence someone took the time to grease the pins and channel. Next, working back on the flex brake lines, make sure you don't have leaks at the calibers or the connector block back up line. On the ABS unit, would check the lines on it to make sure one of them is not leaking, and then pull the controller on the unit to check the valve seals to make sure it not leaking there as well. On the master, would take a good look at the back side of the booster to the firewall, to make sure it not dumping fluid out of the master as well. Hence if the master is leaking, it going to dump into the brake booster.


As for bleeding the C6, you have to use a tech II to cycle the ABS valves and ABS pump to get the air out of them to start with.

From there, basic pressure power bleed to push out the last of the air once it has been cleared from the ABS unit towards the back of the car.

Last step, is one more time with manual brake pedal pump up/jolting per caliber with power bleeder still on the car with pressure, to get any air bubbles off the caliper piston seals to flush out of the calibers to get the pedal rock solid in the end.

 

You never pump the brakes while the bleeder is open!

 

Better trick, is to treat the car like a C5, and leave the brake pressure bleed on the car, until you are completely done; including the final pedal pump ups/jolts to break the air bubbles off the inner surfaces that may still be in the system. This way, if someone does hit the firewall with the pedal as the bleeder is opened, the system is not sucking air back in, since the power bleeder is pushing the fluid out still.

And if you don't use a tech II to first cycle the valves and pump to get the air out of them to begin with, your really pissing in the wind and the pedal will never become hard.

 

The Corvette is a very fast car, one make's "track pad" is not another, if you're hard on the brakes (or traction control / active handling is always engaging) than likely its your pads. The HP+ appear to have similar specs to alot of autocross pads and not track day pads. Without knowing what you're doing, i'm guessing you're overheating the pads.