The Brembo brakes on my '82 LS pulsate slightly. It is only noticeable at very low speed (when coming to a stop) but actually causes the forks to compress/decompress slightly ,once with each wheel revolution. The bike has 14k miles, the rotors are just over 5mm thick, not scored, not rusted, look great, and the runout is 0.002" (R) and 0.003" (L). The brake lever does NOT pulsate. So, before I spend a fortune on new rotors, is there something else I should try? That runout seems pretty low to me, but maybe that amount is significant.
So far, this is what I have done: installed stainless lines, replaced the fluid, cleaned out calipers, cleaned pistons, and installed new seals. Sanded the pads, sanded and cleaned the rotors twice. I've put a few hundred miles on the
bike with no change. I will say, except for the pulsation, the brakes work great!