if is all 4 (mine was both rear = rear brake hose split) all 4 is the - "something brake valve" __ some one help with the correct name here ! -
a control valve near the abs setup, its not part of the abs could be stuck or faulty..,
OR, bleeding the lines is good, but does not mean that they are 'good', it does seem unlikely that all 4 (5) brake lines fault at the same time, but when a rubber line faults the inside puffs/ swells/ restricts the flow, so when cold it bleeds well, and the wheels turn freely, but hit the brakes hard a couple times and the fluid compresses on the brake side of the hose, keeping the brake on, till it slowly releases back to the system.
Jeep Grand Cherokee 1995 v8 5.2 185000