brake troubles i searched but no answer

[plymouth383]

i have a problem slowing down. i have r1 concept cross drilled and slotted rotors. my problem is this. if the pads and rotors are fresh cold i have no problem doing an almost lockup stop, now after the pads and rotors get warm i can try the same stop but the pedal goes down to the floor and the car slowly stops meanwhile the pads get so hot they billow smoke from beneath my wheel well. i have replaced the front pad with ceramic pads but it still does it. like they have to much load. has anyone ever had issues with the rear calipers maybe not grabbing and causing too much frontal load. it gets dangerous because i dont know how hot the pads are and sometimes it doesnt like to slow this beast down. could my front calipers cause this... or maybe air in the system... im going to get some self bleeding screws and try to bleed all around but this problem sounds weird. ive thought of everything but nothing makes sense. anyone have this problem. thanks for any help

 

[JC1994]

that's crazy :shifty: I also have R-1 rotors and no problems. sounds to me like you may need new calipers. yours could be hanging up and dragging causing your pads to get hot.

 

[Frogman]

You may want to try and bleed the brake system.

You have to do it in a proper sequence:

1. Rear Passenger
2. Rear Driver
3. Front Passenger
4. Front Driver

 

[Dominus]

Brake bleeding first, then if not, caliper replacement.

 

[plymouth383]

update

well i will try bleeding. i am going to go to napa and get some self bleeding screws and do the whole system. anyway tonight when i was driving everytime i would press the brake with about 20 % to lockup it would turn on the brake light on the dash briefly. i checked the fluid and its full, can these systems detect minor amounts of air in the system or is there another problem. thanks

 

[Frogman]

Well. could be that the master cylinder seal is leaking. But if the light comes on briefly, it sounds like the fluid in the reservoir is going below the minimum level when you step on the brake pedal, which could indicate air in the brake system.

Or it could be some gremlin playing with the wires.

Either way, bleed the brakes and report back to us. Just make sure you keep adding brake fluid. Don't ask, I ran a brake system dry once.

 

[plymouth383]

well i found the problem. when i started to bleed the system the passenger rear caliper had no fluid going to it... after disconnecting several fittings i finally found the clog in the proportioning valve. i took it apart and cleaned it up.... bled the brakes and everything is working perfect. im guessing the system still had the original fluid from the factory because it was almost black, but now i have synthetic dot4 fluid coarsing through the tubes. the rear pads havent even worn the zinc off of the rotor yet. im supposing once the fluid got warmed up it slid past the clog a little bit causing the pedal to drop to the floor and the braking power to go down significantly. thanks to those who tried to help.

oh and for those of you thinking about getting r1 concept rotors... do it. they are cheap and even through all the heat from this outing, they still are in perfect specs and have no heat spots or cracks and believe me if its billowing white smoke from the wheel wells they are very toasty, after running down the road and braking like this i couldnt touch the wheels for hours. if anything should warp.... these should have by now but they are perfect. thanks again

 

[JC1994]

I agree on the rotors, mine saved my ass a few weeks ago.