Brakes locking up.

I'm thinking if the brakes release by cracking the line at the M/C,, that a rubber hose will only hold pressure in an localized area,,

I think the M/C rods outta adjustment, if you changed M/C.. or if it's the original Master cyl, it still has a residual pressure valve in the front system (re Dubob).., or the M/c cups have swollen..

hope it helps