If it is the airline that has fractured my bet is it will have done so where the line enters the tailgate door as this is the only area that moves. If earlier threads are correct pressure does lock and vacuum opens. If fracture occurred after the lock was in a closed position, then as there is no vacuum to open it unless access to the line between lock and fracture or at the point of fracture is made, one would seem to be snookered. Hence my original question was the lining removable with the door closed.