both front brakes keep locking up

Both My Front Brakes Keep Locking Up On My 93 Pathfinder, I Can Take Power Booster Line Off And Calipers Will Go Back To Normal, But Brakes Will Freeze Up In About 3 Miles Agian ,, Please Help Im Stumped,, Thanks Roy

check your power booster hoses for any cracks/holes, make sure your clamps are strong.
check your fluids for air, bleed them.
check brake lines for leeks, if nothing still, check nissan or a trusting certified mechanic
good luck