Chev. G-30 front brake lock up



After driving 6-10 miles the front brakes begin to lock up and won’t release untill I crack open the bleeder valve. I’ve replaced both front brake hoses. Would the proportioning valve cause this ? It’s allways 6-10 miles before locking up. WHY ?


How old is the van? Have you ever changed the brake lines? Sometimes when a brake line deteriorates they form little baffles that keep the brakes from disengaging fully.


I have had that happen due to a master cylinder problem, does it affect both front brakes?


It seems to affect the front right brake more but yes it attects both sides