my sisters civic calipers LOCKED UP...
she drove it 1 mile home and the pads were smoked

I thought i could just change the pads, turn rotors and bleed the system.
and it worked fine for 1 day then her calipers locked up agian after driving a while.

If we let the car sit for 1 hour the calipers UN-LOCK themselves & the car can drive.




Q:
when she drove the car home 1 mile with the pads touching the rotor, she probably boiled the brake fluid.

DO i need to completely FLUSH the brake system? if so how do i do that?
special tool?

 

Hmm...

I'm not an authority, but it sounds as though the pistons in the brake caliper are seizing.
Highly suggest new calipers. Driving with the ones on the car now is extremely dangerous. It sounds like your piston(s) seize under normal load then require time to slowly unlock. Common problem.

 

Was anything done to the system before they locked up? Like mentioned above, check the calipers for proper operation. Make sure that the sliders move freely.

Regarding the flush, I would drain the MC reservoir (use a turkey baster and leave a small amount in the bottom), refill the the reservoir with fresh fluid, and then bleed the brakes.