I have a 95 z34 and the amber ABS light is on as well as the red brake light. fluid is good, front pads are good driver side rotor has a pretty deep score in it and knife shaped on the outer side. Brake pedal doesnt feel stiff enough like it almost goes to the floor and takes some foot strength to come to a stop plus i feel pulsation. Brake lines are good and sanded and lubed the caliper bracket contact points and lubed the bridge pins. Does any one have any reasons why these lights are on??????

 

Brake fluid level is good and you can almost get the pedal to the floor? Maybe the master cylinder is toast. Does the braking power seem to increase if you pump the pedal? This is what I've seen before with a non-abs system. I'm not an expert on ABS though but it seems that 'might' be attempting to work since you feel the pedal pulsate. Just my 2 cents.