crazy rattling in highspeed while braking;;

[llozll]

like i said in the title, there's a crazy rattling in highspeed while braking.
it started to happen after upgrading my front brake to zbrake.
well i recently changed pads to see if it will fix it, but still..
would the rotor be the one causing problem?
what is your suspect?

oz

[cheap_sticker05]

Did you have your rotors turned if they were used? Did you change the rear brake pads without having the rotors turned? Brakes rotors and pads should be replaced in pairs. Alittle more info would help too.

[Nizzan4u2nv]

Resurface your rotors.

[llozll]

yea i did resurface the rotors front and rear and pads are changed in pair:)
to add more info, it rattles mostly from the front in high speed, and stops as car slows down. should the rotors be replaced to new ones?

o z

[nrg]

warped calipers.

I have the same problem right now but it's not too bad. It happened ever since I swaped in brand new brembo rotors. my problem is most likely bad tires.

[llozll]

are u still having the problem, then? or fixed?

caliper seems fine by looking at it.. but juss wondering how it could get warped..

u said ur problem was most likely bad tires, then w/ new tires will u be ok?

[NIK90s13]

Are you getting any viberation from the pedal?

[nrg]

zero vibration in steering or peddles. it's just that when i stop hard, the braking sounds alot different than it used too. it's either the new brembo which doesn't like autozone pads or bald tires. the problem i have isn't a big deal, might not be like yours tho. Are your calipers put on correct? the bleeding valve should be on top of the calipers; which is what judge which side goes where.

[i20ar]

are your calipers slotted or blanks... your using autozone pads? if its sloted.. that could be whats the problem.

[nrg]

yea my rotors are sloted/drilled. i wanted blanks but 88rotors.com didn't have any in stock. :(

nopi sells z32 blanks for 25 each btw.

[i20ar]

i think i read somewhere the slotted rotors need a certain type of pad that not as hard as the conventional ones.. the slotted rotors will wear down your pads like a cheese grader

[nrg]

yea i heard the same. but my pads are lifetime from autozone!! =D

[shayrgob240]

zero vibration in steering or peddles. it's just that when i stop hard, the braking sounds alot different than it used too. it's either the new brembo which doesn't like autozone pads or bald tires. the problem i have isn't a big deal, might not be like yours tho. Are your calipers put on correct? the bleeding valve should be on top of the calipers; which is what judge which side goes where.

what do your tires have to do w/ this prob?

[llozll]

i get the vibration not from pedals but from steering wheel.

and i noticed that it only happens when i brake on 60mph or faster

[daryl337]

with slotted rotors, it does not matter whether you get organic's or semi metallics... they are going to slice your pads either way. Ceramic pads will last longer under high heat braking, but are sometimes a harder grade material than most stock rotors, in which case the rotors get F*'d up.
Essentially, if you go to a softer pad, they are going to be eaten up faster no matter what kind of rotor you get, however with a slotted rotor... you dont have to worry about your pads glazing over from high heat braking due to the fact that it "shaves off" a piece everytime leaving you with fresh pad.

As for your problem, is it always just "high speed braking" or is it "high pressure braking" that is the problem? In otherwords, can you be going lets say... 110 mph and lightly touch the brakes and you get vibration, or can you be going 50 mph and brake hard.. which gives you a vibration in the front? If it is a high pressure braking problem that gives you a vibration, then it is more than likely rotors/calipers, with a possibility of a small suspension set up problem (alignment/wheel balance)... however if it is a high speed only shudder, it is more than likely a front wheel bearing problem, or alignment/wheel balance. The reasoning behind my "online diagnosis" is that when you brake lightly at high speed, your weight barely shifts to the front, but because you are travelling at high speed... any vibration in the bearings/balance is more than likely going to be amplified (because your wheels and tires are spinning faster)... however if it is a "high pressure braking problem" then I would look more towards the brakes due to the fact that the calipers are applying alot of pressure to the rotors, and you are probably feeling it there.