We've been having a problem with the back tank smell in the trailer.
Empty and clean we could smell the deodorizer too.
I climbed up on the roof to check out the black tank vent.
Once I removed the vent cap,
I notice that the vent pipe didn't even come to the top of the flange.
I could wiggle the vent pipe and suspected that the pipe wasn't sealed where it went through the roof.
I removed the flange for a better inspection...
The 1 1/2" black pipe went through a 2" hole in the roof.
It was not sealed and I could see Styrofoam and wiring through the opening.
Could this unsealed vent pipe opening be causing the odor?
I think it probably is.
I used backer rod to seal the opening and flooded with dicor.
While I was up there I replaced the vent with a cyclone vent made by Camco.
I hope this fixes the smelly problem we have been having.
If you have been chasing black tank odors in the trailer,
check where the pipe goes through the roof.
Time will tell if this was the cause.
I hope it was.
If I can figure out how to add pictures I will.