Spent the past 2 days replacing the toilet & vent grommets. Quite a job, but now done & hopefully no more smells.
The toilet grommet was ok, turned out the smell was due to the vent grommet. Black water was escaping around the grommet, there was dried brown crusty stuff visible. I believe this issue was due to a bad install originally. A year ago, trying to solve the smell problem, I had to extend the vent pipe, because is was too short to go into the grommet. In hindsight, I should of removed the fake wall to better see what was goin on.
In our coach, the vent pipe is located behind a fake corner wall in the bathroom. I removed the toilet, medicine cabinet & opened the corner wall. Disconnected the cable ties holding wiring to the pipe, removed vent cap & was able to push the pipe thru the roof. Here I found another problem. There is an L bracket secured to the pipe with a hose clamp. The bracket is supposed to be screwed to the floor, keeping the pipe from lifting out. It wasn't, but the screw was laying there
I could see the grommet, but could not get my hand thru the hole, & could not reach it from the toilet hole. (Sharon, with shorter arms could, but not enough strength to wrestle the grommet out). So I enlarged it with a key hole saw, enough to get my hand thru & remove the grommet. I didn't think I was going to be able to put the new one in, really difficult, but after about an hour I managed to do it, getting the tank top into the grommet ring was a tussle. Put the vent pipe back into the grommet, with help from a little soap, & secured the L bracket to the floor.
Toilet tank grommet was easier to install. I got everything back together & no water leaks. Hopefully no black water leaks also.
I will post some pics as soon as I get them organized.
While I had the corner open, I snaked a cable out to the water bay. I installed a door bell button, which I will use to operate a relay to turn on the water pump. I think I can wire it into the water pump switch in the bay. This way we will be able to turn on the pump to flush toilet at nite (I am also one of those who leaves pump off at nite). I decided this would be a lot easier than trying to add a third multi switch. I will post results in another thread.