right front brake locks up and will not release. what makes this happen? hoe do on 1993 GMC Safari

I replaced brke calbers on both sides bleeded them but still it locks up and will not release. WHY ?

3 answers
REPLACE THE FLEX HOSE, IT HAS COLLASPED INTERNALLY, PRESSURE WILL APPLY THE BRAKE BUT WILL NOT RELEASE COMPLETELY.
Yes HOE do have to change brake hoses David Adamson.
never mind........