i have changed the brake lines,pads, calipers and the brakes still lock up on 1997 Chrysler Sebring

When the car is cool it runs great but after u use the brakes a few times they lock up

Asked by for the 1997 Chrysler Sebring
It could be the master cylinder not returning fluid to the reservoir or if the master cylinder was just replaced perhaps the push rod to clearance to booster has not got sufficient free play.