Black8Banger

iTrader: (9)

Something is wrong with my brakes!
Running the 1/4 mile Im trapping around 116-118 and as soon as I cross the finish I get on the brakes. I can BARELY get the car stopped before the track runs out! I have the take the very very last turn off. I have had the ABS kick in before on the 10 bolt and now with the 9" the brakes want to completely lock up if I dont feather the brakes. I have stock calipers, brand new rotors, lines, and pads! There is nothing wrong with the calipers, pads or rotors. On my dads 99 Z28 you barely tap the brake and it grabs and stops QUICK! On my 99, I press the brake about 1/3 of the way down and it starts to grab but doesnt grab near as hard! Does anyone have any clue what is wrong and how do I go about finding out what the problem is? I appreciate any help!!

Thanks
Josh

aluminumblockCock

yea that is weird.

JackZ28

Try bleeding them and see if that helps. If it doesn't, you might want to try a different setup. What brakes do you have on the rear? Without ABS, it is going to be much different, but you should still be able to brake.

Black8Banger

iTrader: (9)

I just got done bleeding the brakes @ every single point possible, including on the block as well as at the calipers. There was no air in the lines. Test drove it, everything is still the same. Took the calipers off and there was something a little funny on the front passenger....the top half of the pad was wearing thin but the bottom half wasnt wearing near as much. It looked as if only the top piston was working all full force in the caliper. Also, on the rotor and pad there were very obvious heat spots, like the pad and rotor are heating up very hot in only certain spots. Maybe that was from braking at the dragstrip and not street braking, im not totally sure. I checked all the lines and nothing is pinched or bent.

The car has ALWAYS acted like this, even from the day I got it. Of course during the motor swap, we swapped all brake lines, calipers, new pads and rotors and it has still stopped the exact same way. The only thing that wasnt changed was the brake booster and master cylinder. Has anyone ever heard of this stuff going bad? If so, how do I check it? The vacuum hose is also still connected and in good shape so thats not it!

Josh

TooSlow02

Did you disable the ABS? If you did, then you lost your brake proportioning, since it is electronic on LS1 F-bodies. That means that the rear brakes are receiving full line pressure, and the result is severe overbraking in the rear. You won't be able to get the front brakes anywhere near full braking with that setup, since the rears are locking so soon. Install an adjustable proportioning valve in the rear brake circuit between the master cylinder and the ABS valveblock, and turn down the rear apply pressure until you can get the fronts to lock before the rears do.

BTW, the stock front brakes on LS1 F-bodies are a little lacking. Try some more aggressive pad compounds; you can great pads from companies like Hawk, SBS, Wilwood, Carbotech, EBC, etc. If you can swing it, try upgrading the calipers also. You can use C5 Corvette calipers with the stock rotors, or you can use the C5 calipers with stock size C5 front rotors by installing Bob Bishop brackets. It's a pretty good bang for the buck, and I think you'll like the way it stops.