High-speed braking problem

[Mystikal]

Have a rather unsettling braking problem that only happens from very high speeds, i.e. 110mph+. Starting a few months back, I was getting a very bad vibration, which I attributed to warped rotors and completely gone wheel bearings. I replaced them, and at sane speeds everything is perfect. However, if I am slowing down moderately or harder from very high speed, by the time I get down to about 60mph, the front brakes begin to make a grinding noise (almost sounds like a completely worn down pad) and braking performance fades away to about 50% of what it started out as. I'm thinking maybe it's the pads, but I'm not too sure.

This is the current setup:
Front: Brembo O.E., Pagid non-sport
Rear: Whatever the dealer puts (not my work)

Any thoughts? I'm going with EBC Greens next spring, but just wondering if there could be another source.

[spencers]

Man. I have the same problem!

I get vibration from any braking! However I'm not sure of my problem..

[Mystikal]

Um, I don't have any sort of vibration, read it again. And you probably just have warped rotors.

[Jordan]

Yeah, I have a similar problem. Only occurs at high speeds. Yesterday it happened when I dropped anchor from 120 down to 60 for a slow truck. My rotors are definately warped, but when I'm being nice on them they dont shake. For a couple minutes after that they were shaking under any braking tho.

[Rob]

sounds like glazed pads to me.

[BMW BMXER]

sounds like glazed pads to me.

I agree, my brakes used to do that, I swapped my pads its stopped. I posted about it a long time ago.

[rwh11385]

Sorta an issue for me as well. reducing velocity at a quick rate will have car shimmy a little bit. However, I am still impressed with the braking power.

How do pads get glazed?

[Mystikal]

sounds like glazed pads to me.

Good, I'm happy it's the pads. It's really not any sort of shimmy or vibration, just a horrible grinding noise and poor stopping ability. I probably won't be going over 180km/h until winter is over, so I'll put off changing the pads until spring.

Thanks guys.

[Rob]

glazed pads is sort of a quick overheating of the pad

[Mystikal]

That is exactly the description I would come up with. Once they get about 10 seconds of cooling, they go back to normal until the next long braking session. These pads would kill me on a track (something I plan on doing next year). Luckily our auto-x is extremely low-speed, I can still run that on these pieces of shit. Noisy, dusty, plus they can't take heat.

[Axxe]

I get a vibration in the steering wheel @ 140km/h, and it stops at 160ish. Warped rotors or wheels out of balance? I'll have to see what happens after I put my winters on in December.

[Rob]

warped rotors usually cause vibration under braking, since they're a part of the brake system... your problem sounds like the wheels need balancing

[clavinZERO]

Check your bushings and ball joints as well. make sure the whole front is tight as that can also make things vibrate. Your pads sound like they are toast.

[rwh11385]

I've come to the conclusion my loose driver side CA bushing is to blame in part for some wobble perhaps.....if that isn't too extreme of a word to use.

So yeah, check the bushings.

[Mystikal]

Check your bushings and ball joints as well. make sure the whole front is tight as that can also make things vibrate. Your pads sound like they are toast.

Thanks for the suggestions, but for the last time, I have no sort of vibration. And if it were those, it would be causing issues immediately when I throw the anchor.