I had the very same on one of my Sportraks, replaced the disk and no further problem. My other Sportrak has started now and eventually I will do the same. I was told not to drive through puddles when the disk is hot...right.

I think disks wear a lot more nowadays since the dreaded asbestos was removed from the friction pads and the cost of discs has come down drastically. This could be one of the reasons that they warp or wear unevenly but I can't see how you can drive around puddles to avoid them warping.

I agree with the previous comment but I do use coppa-slip but only a tiny amount. You must allow pads to bed in for 400 or so miles and you must clean the calipers completly and ensure the pistons are moving freely. A further cause of judering can be a leaking seal causing the pad to GRAB due to contamination, although in your case I suspect that the seals are fine and any leaks would have been identified.

Of course vibrating uder braking can be caused by worn suspension and steering so you may have a different problem altogether.

OLDMINIMAN

what make brakes are you fitting is the first point
second are you fitting correctly
remove old disc clean hub spotless clean sliders no copper slip on the back BIG NO NO
fit pads and discs then drive very gently for 400 miles not slamming brakes on from 70 mile a hour this warms them up and causes warping
let me know the make you are fitting this could also be the problem been selling parts for 27 years in a motor factors and believe me there is some rubbish makes out there