help s14 front brakes are locking up

[ni5mo240]

front brakes are locking up after driving on the freeway bleed them yesterday helped but happened again today.

any ideas check valve seems to work right master is holding fluid and bleeds fine trying to look up how to tell when a booster is bad.

any input will be great thanks

[iLagX]

piston seized?

[ni5mo240]

Nothing is seized just replaced the booster seemed to be ok but when I went back to move the car the pressure built up in the pedal and now they are sticking again