The toilet flange was broken on the soil pipe. This is a cast iron pipe and flange that was leaded on. I cut the old flange off. Replaced it with a flange that has a collar than fits over the soil pipe and you tighten four bolts that secures it to the pipe. I made sure that it was flush and level with the floor. Now the toilet is loose (it rocks when you sit on it) Can i get another flange leaded on? or is there another way to fix this concern.