I recently bought a 90 sc and it came with a stiff brake pedal, it has been sitting since 98 so I thought maybe the caliper pins were rusted so I took them apart and cleaned them and greased them also put new pads and rotors, but that wasn't the issue, it stops better but is still hard to push, sometimes if it sits for awhile when i first start the car the brake pedal is fine for a couple pushes then goes back to being rock hard, all the fuses and relays are good so its not that, any ideas on what my problem could be? Or where I can find parts for this thing?