My problem was: https://www.rx7club.com/3rd-generation-specific-1993-2002-16/wierd-brake-problem-gripping-while-driving-526313/

"well, im having some brake issues. i did a search, came up with nothing that matches this... so please, no "do a search remarks." anyways, brake problems start when i noticed after starting the car there isnt any pedal presure... after 2 pumps, its back and fine all day. then in the last week, i noticed after driving for awhile that the brakes are actually puting pressure on the rotors, and slowing the car down. they are putting an incredible drag on the car, and from the motor working so hard started to heat up high and i turned off the car. when i engage the clutch and roll the car stops liek im brake, but im n ot touching the pedal. im thinking i have a master cylinder problem. i have not seen any break fluid leaking at all. bu i have no idea why the breaks are grabbing while i drive. i have new hawk pads. been fine for 4k miles. i dont smell breaks either, i figured i would, but i do hear them sqeek a bit when i am nearing stop (with no foot on the break pedal)... so from that i know its the breaks. any ideas?"


A few days ago I purchased a used but good condition brake booster and master cyclinder. I swapped them both out and blead the brakes. And I drove for over an hour with no problems. I drove to work tday (45 mins) with no problems! So I think its safe to say that the problem resided somewhere within the brake boost/master cylinder. I am thinking it was the brake booster, possible went bad from 13 years/86k miles, or a bad check valve allowing boost into the booster itself. I am also changing the one-way check valve just in case. If you have all four rotors grabbing your breaks, and a stiffer than normal pedal feel, try checking the break booster. Hope this helps in the future for someone with these problems!

 

FYI: The parts set me back $225. And about 45 mins to swap parts out, 45 mins to bleed the breaks (I was alone).