Car Shakes When I Brake

[TMW-R34]

Hey guys, i have an r34 GTT, and about an hour ago, i was braking, and the car really felt like it was shaking. i took my hands off the wheel doing about 60 and tried again, and the wheel was shaking like crazy. When i rolling about 20, slow down then jump on the pedal, the sound it makes is like my front bumper is scraping the ground, which i know for a fact is not.

i have checked the front and back pads, both fine, checked brake fluid, fine. checked my abs fuses, both fine.

Anyone able to help me here as why its doing this, cheers guys.

[PM-R33]

Could be warped rotors.

[GBLOCK]

+1 Check out the rotors. They've probably been chewed up.

[TMW-R34]

how do i tell if there warped, what am i looking for??

Anywhere in particular???

[San-Ni]

Jack car up spin the wheel, take wheel off spin the hub....watch the rotor and you should easily tell its warped.... I have the same problem... cheap fix is to take rotors (get both sides done) into a brake specialist to have you rotors machined ($20-$50)

[havoc_r33gtst]

my brother in laws 32 did that it was something with the front suspension get it checked at pedders its like 29 bucks to check.. if it feels like the whole car is shaking then i think thats the prob.. hope this helps

[99 GTT]

As has been said above could be warped rotors or a suspension bush etc, most likely rotors.

[TMW-R34]

no worries guys, thank for the replies.

Il take the wheel off and check it out.

[TMW-R34]

took the wheel off, rotors look fine as a mate said aswell. He took it for a spin and obviously it didnt happen.

He said the fluid may have got so hot and boiled. Has this ever happened to anybody????

[MrStabby]

Boiling fluid doesnt cause shuddering. The other suggestions in this thread are on the money.

[SWITZER]

+1 for warped rotors get them machine

[ARTZ]

is it auto??

Our car used to do it,mainly when going down big hills, where brakes are working hard.

happens alot with autos,Falcodores owners are constantly changing discs but the Rotors arent actually warped, but residue from pads gets baked on to the rotors..You know when u sit at the lights with brakes on, pads are really hot..Apparently some good metallic pads and hard braking can clean it off, but i havent tried it...

Either way get them machined..

no need to take discs off, you can get them machined on car..Any brake place even kmart tyre an auto can do it ,about 110$

Edited June 21, 2010 by Arthur T3

[Deano 1]

def rotors.... get em machined

[paulR32gtr]

brake and shake baby - had to be said

[TMW-R34]

brake and shake baby - had to be said

hahaha nice.

It has stopped the shaking now, well, the day after anyways, so now i dont know about the rotors anymore??

Its back to normal and i havnt changed anything.

[TMW-R34]

is it auto??

Our car used to do it,mainly when going down big hills, where brakes are working hard.

happens alot with autos,Falcodores owners are constantly changing discs but the Rotors arent actually warped, but residue from pads gets baked on to the rotors..You know when u sit at the lights with brakes on, pads are really hot..Apparently some good metallic pads and hard braking can clean it off, but i havent tried it...

Either way get them machined..

no need to take discs off, you can get them machined on car..Any brake place even kmart tyre an auto can do it ,about 110$

Nah mate its a manual.

[ARTZ]

hahaha nice.

It has stopped the shaking now, well, the day after anyways, so now i dont know about the rotors anymore??

Its back to normal and i havnt changed anything.

Dont u love it when cars fix themselves

[TMW-R34]

Dont u love it when cars fix themselves

hahahaha yep, nice and cost effective lol

[Hanaldo]

hahaha nice.

It has stopped the shaking now, well, the day after anyways, so now i dont know about the rotors anymore??

Its back to normal and i havnt changed anything.

My money would still be on rotors. Could have been glazed, but I would still say they are warped...

But also check your tyre pressures. Happened to me on the weekend, felt like something was very very wrong, like the wheels were about to fall off, steering wheel shaking violently, car wasn't handling properly... Checked the tyre pressures the next day, and they had dropped quite low. Pumped em up to 38psi and that fixed all the problems. I doubt you are experiencing the same thing because my problems weren't while I was braking, more while I was cornering. But worth a go anyway.

Edited June 23, 2010 by Hanaldo

[gslrallysport]

Falcodores owners are constantly changing discs but the Rotors arent actually warped, but residue from pads gets baked on to the rotors..

That's actually the cause of 99.9% of shudder. It's called DTV (disc thickness variation) and is caused by cheap pads, and/or excessive float in wheel bearings... which leads to the pad material being laid down unevenly.

It's VERY VERY rare that rotors actually warp. It simply doesn't happen, even on race cars. Even rally car that get them glowing hot then go through water spashes don't 'warp' rotors. It doesn't happen. It will be DTV. Machining them will fix the problem, but it often doesn't curing the underlying problem.

Commodores are really bad for shudder, and it's always excessive float in the bearings, which starts the problem, then the pad material being laid down unevenly on the rotor because it's not rotating square finishes it....

Some light reading by car engineer legend Carrol Smith:

http://www.stoptech.com/tech_info/wp_warped_brakedisk.shtml