Brake Shudder

[BHDave]

Hi guys,

What exactly causes it?

My skyline has done 5 wakefield days now with no brake issues. it runs r34Gtt calipers pmu HCR pro rotors and HC+ (0-850)pads plus briaded everything, rbf 600 fluid and master cylinder stopper.

The silvia i ran yesterday has aftermarket 32GTR rotors, non slotted but curved vane so i assume a quality product (possibly pmu based on the colour of the hat), 32GTR calipers pmu type NR pads (0-650) plus all the same other stuff as the skyline. In the end it had to be retired as the shudder was getting unbearable.

Is it the rotors? the lack of slots? the pads? I don't want to be machining rotors after every event or i'll have nothing left.

[l_uk3y]

If its anything like my dads falcon ute stocko brakes (no comparisn i relise) It gets the same problem whenever you brake really hard from over 100km/h it gets the shudders and needs machining.

Now i could be wrong but to my knowledge at least in that particular case i think its soft brake rotors warping due to heat. Perhaps that could be the cause in your case that the brake cooling was insufficient causing the rotors to warp?? im sure theres more experienced people to comment then me though.

Luke

[blind_elk]

Wheel bearings? Slop in the steering rack? Steering rack bushes? Castor rod bushes?

[Risking]

had a similar issue with the GTR.

Checked the rotors and found minimal run out etc.

In the end I had a dynamic wheel allignment done and found that the rack mounting bushes were allowing the rack to move side to side under brakes and when cornering obviously.

Easier and far cheaper test is to lever the rack with a bar and see of it has movement side to side.

Pulling the bushes out revealed the insides were oily. I cleaned them up and refitted it was good for a few meetings before the problem came back. I replaced the rack bushes and have never had the problem since.

Perhaps something to have a look at.