CRX - Violent shaking under breaking

[bvondran]

All,
First time poster, but I've lurked here for a long time. I need some help.

I did a pdx this weekend at Nelson
Ledges and my car developed a violent shaking under light braking before the kink. It was an up and down oscillation, not a side to side shudder like warped discs. And it was violent at times, like I could see the dash oscillate up and down. There was a slight vibration under braking for 12, but nothing like before the kink.

The car is an 88 crx prepped for ita. New front pads (hawk dtc 60) and new front rotors. Rears are old and could be the culprit I guess.

What about ball joints or bushings, could they be causing such an issue? Or maybe the pads are cooling down too much?

Any help would be greatly appreciated.

Thanks,
Brian

Edited for additional description.