had the same problem with a landy we used in mozambique to launch dive boats,the salt caused the drums to fuse with the brake shoe material.i used a cutting torch to heat the drum and burn the break shoe,then gave it a good few bashes with a 4 pound mallet and it came off.only heat the outer ring and not the face or you will stuff the oil sealin the hub.park the landy outside as there will be plenty smoke