Why is my ABS / Brakes locking up?
 

So im driving my FD the other day going down a hill w/ light to moderate braking, it rained earlier in the day the ground was damp not to wet. coming up on a red light i was on the brakes gradually just normal braking down hill and all of a sudden the brakes were locking up and i got freak out because i was headed straight towards another cars rear bumper so i let off the brakes and got back on em and they locked up again but thankfully it stopped in time. i decided to try it again on another day when it was dry out on a flat road i pressed the brakes gradually harder and harder and after a while they locked up again. is this normal abs characteristics on these cars? i had no abs lights come on and they do work.

This is definitely not normal. You should feel the pedal pressure modulating as the ABS keeps the brakes from locking up. I am no ABS expert, but the first thing I would do is check the standard brake components for wear. Cover your bases first, then move to the more complex components.

The FSM should have the procedures to test the ABS. I would start there.

check return ports.do they stay locked or do they free up as soon as you let off. my fronts would stay locked and slowly release. even with regular fluid changes and flushes still get gunk build up after 20years