I have a older home and it has 2 bathrooms, one is a full bath which was built with the home in 1954, the other is a half bath which was added at a later time and I don't know if it matters or not but they are on opposite sides of my home. The problem I am having is when I flush the toilet in the full bathroom it makes the toilet in the add on bathroom gurgle. How do I fix this? Let me give you some so background on what has been going on. First I noticed when I flushed the toilet in the full bathroom the kitchen sink and the half bathroom toilet would make a gurgling noise and air bubbles would come up in the half bathroom toilet. Also when I flush the toilet in the half bath it would fill up and then drain really slow. So then I came home and it smelled like sewer in my home so I went to home depot and rented a 75ft snake so I pulled up both toilets, I went to the washer room, and under the house to a clean out and ran the snake all the way out to the road and I did find some clogs but now I know they are gone. So I thought I had the problem fixed but now when I flush the toilet in the full bath it still makes the toilet in the half bathroom gurgle and air bubbles come up I guess on the good side the kitchen sink no longer gurgles... so I guess I have a vent problem?? I looked on my roof for the vents I seem to have three, one for the full bathroom, one for the kitchen sink, and another for the add on for the bathroom and washer room... but both have covers on top of the pipes to help keep things out of them so I am lost please help?? If I need to snake the vent pipes what should I use?