Kitchen sink is backing up water on both side. Customer said when he run the disposer the water go to the other side and when he trying to plunge the other side, the water would go back onto the disposal. I remove the air admittance valve and run a flex shaft from there up to 30 feet. Clear out the inside of the pipe wall to wall and break down all the greases, pipe are running very good run a lot of hot water to test it out.
