Ok so I have two drain lines going down into my slab that are broken flush or darn close to being broken off flush with the slab. I bought a hammer drill and was going to break around the drain rougly 2 to 4 inches deep and then I was going to couple the pipe with these rubber couplings and fill in whatever I broke out with this hydrolic cement. Am I right by doing what I am doing or should I go a different route? Any advice is greatly appreciated and I say thanks in advance.
The rubber couplings can be considered a temporary repair. As such they should not be partially buried in concrete.
The really correct fix here is to remove existing concrete to the point that a proper connection can be made to the existing piping that can bear up to being a permanent type fix that can be embedded in the replacement concrete.