Pressure on the throne!

TakingThe5th wrote:
Our water closet/commode/throne/toilet seems to develop a bit of pressure a day or so after the start of a trip. When that happens, a giant bubble will appear immediately as I flush, follows by a "wonderful" smell. This doesn't happen on day 1, it might be day 2 or 3, and when it begins it usually persists until we dump and rinse the tank.

Also-the first day the throne begins leaking at the base, but that may stop the next day, or not. Need to tighten the toilet hold down bolts.....OR foam seal was not installed correctly.

I ran a stream of water down the vent and it's open. It didn't seem to be clogged as well as I could tell. As I ran the hose down the vent I also pulled the black dump valve and was surprised at how clean it appeared, hardly anything-no paper, a little bit of "other".

I've been going really heavy with the toilet treatment just to cover that base. Just two people in the camper, myself and DW.

This is our first year with our Cougar 333MKS and I'm thinking that the vent stack may be installed too deep into the tank. That is my best guess and I'm thinking I should take it in under warranty. Correct..vent pipe was installed to far down into tank OR has slipped down.
Waste tanks are not very deep........long, wide but shallow. So wouldn't take much of a level to block off vent line if it is too far into tank. Then tank cannot properly vent until you open toilet flush valve....then it has a place to vent. Right up thru toilet at you!

Any thoughts or ideas???