Rubber brake hose stuck

[Codifex Maximus]

I'm rebuilding the rear brakes on a 84 300TD Wagon and the calipers have wear on the contact area. Rotors are totally shot - eaten clean thru. Nothing left of the wear surfaces of the rotor but what looks like a rusted metal ring.

I've got all the new parts and am attempting to replace the rubber brake hoses. Only thing is... I can't get the old ones to come off!

Is there some trick to this procedure?!

I'm using special metal hose wrenches to avoid damage to the metal line. I haven't put much torque on it because I'm afraid of damaging the metal line. I'm using another wrench on the plastic side of the hose connection. I've inspected the new hose and the threads appear standard.

When I try to turn the 12mm metal fitting on the rubber brake hose, the metal line and it's 11mm fitting try to turn too. Put the special metal line 11mm wrench on the 11mm fitting to keep it from moving while I try to turn the 12mm. No go - 12mm side wont let go.

Searched the forum and found no previous instances of this issue. Advice?