cast iron drain connection

[miamivice25]

I have a home with a crawl space and I have discovered that one of the cast iron drain pipes connecting to the main drain pipe has rust and cracked. What is the best way to repair this drain pipe? Also is there a way to loosen up the piece of the pipe still connected to the main drain pipe?

[Java_Bob]

the illustrations section shows this

[miamivice25]

cast iron piping

I am not familiar with where these illustrations are. Please assist.

[HayZee518]

parts of a cast iron are the hub and spigot. the larger part is the hub, the other end is called the spigot. CI pipe is put together with the spigot into the hub. Oakum is then pressed into the joint and "caulked." caulking means the oakum is tamped into place with a flat chisel and a 5 lb hammer. Next a rope dam is placed around the hub and molten lead is poured into the hub. when the lead hardens and cools a bit the chisel is brought into play again and the lead is hammered into the hub. Now days the oakum is still used but a two part epoxy is used in place of the lead.
to repair your problem the bad section of pipe needs to be removed. easiest way is with a tool called a snapper. you can rent one of these at a rental center. it is a chain with cutter wheels on it. you wrap it around the pipe, tighten the clamp and tatchet it back n forth until the pipe snaps. Next get a piece of cast iron and cut the replacement size. Use a furnco rubber coupling to splice into the pipe you cup. use the oakum and epoxy on the hub end.