Car Shakes When I Brake

[MrStabby]

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.

GSL - i've had that before, and it was clearly visible as differently coloured areas on the rotor. Is it always visible?

[gslrallysport]

GSL - i've had that before, and it was clearly visible as differently coloured areas on the rotor. Is it always visible?

Nup, not always visible. You only need a few thou in thickness difference for it to occur.

[kylegtr]

even a slight warp which you cant see is pretty noticable, not to mention annoying

[TMW-R34]

even a slight warp which you cant see is pretty noticable, not to mention annoying

but its stopped doing it all together, cant feel it at all????

[TMW-R34]

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.

Will have to check that out, better safe than sorry

[Hanaldo]

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

I warped my standard rotors by getting the rotors hot and then sitting on the brake when I'm stationary, like at a traffic light?