brake wobble

Hi,
My 97 xj occasionally has a brake wobble whilst braking from 60 down to 50mph. The strange thing is it doesnt always do it. (most times it doesnt do it)
ive read warped discs as the culprit but if my discs are warped shouldnt it do it all the time? Even if its only through the speeds mentioned above?
brake pressure doesnt seem to make a difference. Its like the wobble/vibration has a mind of its own as to when it does it or doesnt do it!!
It brakes in a straight line and doesnt pull to one side. Just occasionally it gives me this brake judder. I dont think that the judder is felt on the brake pedal its just like the dash starts to judder.
It doesnt give me the judder when going over bumps etc its only intermittently whilst on the brakes at those speeds?

Pitted and bad spots on the brake rotors will cause it.. You should feel it pulsate through the brake pedal..

Nick

my guess would be warped brake rotors that are causing the vibrations at certain frequencies at those speeds like death wobble would. i wouldnt rule out the possiblity of warped rotors just because the symptoms dont perfectly fit.

how long ago since you replaced the rotors and pads? if they are almost due, i would just go ahead and replace them anyway and see if it solves the problem

a loose/ warn hub or TRE can give you the shakes too-- and isn't transmitted through the brake pedal as much

ive had the front tires toed-out too much and made for some crazy front end braking.