Drainage problem question

[Estam]

This has been an annoying problem we've had for years, a slow draining bath tub to the point now it's a no drain bath tub. The nut at the top of the down shoot I have completely rounded not realizing it was brass and adding too much pressure. There is very little clearance and is below the floor level. My last resort is to get a small grinder and grind a slot in the nut and apply a piece of bar stock and give it to her. I have my droughts whether it is going to release.

I have a sink that drains into the down shoot just a little below and it drains well so the problem I see is a blockage at the end of the pipe that enters the down shoot. My question is what can I put down the pipe that will work around the 90 degrees and get threw the maybe rust build up at the end. Any suggestions please.

 

[Estam]

 

[nealtw]

Have you tried a snake.
https://www.rona.ca/en/cobra-plunge...MI97W9zeuO5AIVCcRkCh3mDgDcEAQYAiABEgLb-fD_BwE

 

[Estam]

I like the idea, will it negotiate 2x 90 deg bends in that size of pipe?

 

[nealtw]

All you can do is try.

 

[Fireguy5674]

You can remove the brass cap with a hammer and chisel if you can get in there and replace it with another brass or plastic. I have seen very few of those ever come loose. Those caps are very thin and are not hard to break. Probably don't even need the chisel. When removing them at a sewer cleanout they get about two tries with a pipe wrench and when they don't move the hammer comes out.

It is a little hard to see exactly how things run in there but it appears to me that the cap is part of a drum trap. Almost impossible to get a snake through a drum trap. It won't hurt anything to try but most likely you will have to remove the brass cap.