Brake Shudder

[vstyan]

I started getting some very slight brake shudder that is mainly noticeable at highway speeds and was wondering what could it be? I bought my 97 M3 in March and it has 65k miles on it now. It had it brakes done at around 53k.

I tend to be very careful with my brakes (no slamming) and was wondering if it could be deposits that are causing this... Would hard braking get rid of this or is this a sign I need new rotors?

Any help would be greatly appreciated.

[BSR423]

Rotors are warped. A lot of times this happens when people drive their car for a while , get their breaks hot & wash their car. When you cool the metal with cold water really fast it tends to warp the rotor. You can take your car to a shop & have the rotors machine cut , but you might as well get new rotors. Width is important.

[SG_M3]

Its probably not a warped rotor, only pad deposits. Try rebedding the pads, and see if that works.

[Suneal]

Try using a hose to cover all of your rotors with water (both sides... use LOTS of water). After you do this, let the car sit overnight. When you check it out in the morning, there should be a nice layer of rust on the rotors. Then, go out and do some semi-aggresive stops from, say, 30 mph (don't slam the brakes, but use enough force to engage ABS) while going in REVERSE. This is one method to get rid of pad deposits.

If that doesn't work, get this:
http://www.newmantools.com/flexhone/fh4r.htm

[Bernanke]

i hear slotted rotors really help b/c they constantly scrub away at pad deposits and etc and there is no "ball bearing" effect.

[RRSperry]

i hear slotted rotors really help b/c they constantly scrub away at pad deposits and etc and there is no "ball bearing" effect.

LOL... The deposits are on the rotor not the pad... and "ball bearing effect" ? WTF???

[Bernanke]

LOL... The deposits are on the rotor not the pad... and "ball bearing effect" ? WTF???

YES ball bearing effect. its where particles from the brake pad become loose and become lodged between the rotor and the brake pad preventing a solid contact surface. this greatly reduces brake efficiency, Slotted rotors provide a groove for these particles to exit and thereby greatly increasing brake efficiency as well as providing additional cooling.

[mlytle]

slotted rotors (or drilled ones for that matter) are a complete bling item that serve no purpose on the street other that to use brake pads faster (can you say "cheese grater?) and make your wallet lighter....they don't stop faster or channel away "particles from the brake pad"....

as to cooling, slotted rotors take metal mass away from the rotor, thereby decreasing its cooling ability. the original concept was that they would help allow the offgassing that occurrs when brakes pads are used hard repeatedly to dissapate. those conditions are never reached on the street.