I have a wash machine that discharges into a 2 1/2" PVC drain pipe. That pipe is then bottlenecked to a 2" PVC pipe just before it enters a 2 1/2" cast iron main. (At least I beloive it is a 2 1/2" main.) The problem is that the washing machine often backs up and I have snaked out the main and everything seems clear. I suspect the bottleneck is most if the main problem. My question is how to remove the 2" section of PVC and go 2 1/2 " all the way to the main. Obviously the problem is the transition to cast iron. I will try and uplaod a picture of what is there... but this will be my first attempt at that, so I hope it goes well. :-) Dan

http://welchenergyservices.com/pipe%20junction.jpg

I have attempted to post a picture here that applies to my earlier question. What is puzzling me is the fitting from PVC to Cast Iron. Does this unscrew? Is it an oakum filled joint? I am completely unfamiliar with CI plumbing.

Thanks for your help!
Dan