Vent for black water tank?

[bwhitaker]

So does anyone know if the 1971 overlander had the vent for the blackwater tank leaving the airstream? My open end is into the space between the aluminum shell and the interior lining. This was never a problem until today when the temperature got to over 80°F. There is nothing in the black tank either (waste). Now the inside smells like you could imagine...

[bwhitaker]

Well, doing a quick search of Google images shows a few of them do have a vent. So...my next question is...what next? Do I cut a hole in the shell, install a vent and somehow pipe it from the vent down to where the existing vent pipe ends?

[Lumatic]

My 71 Tradewind black tank is vented.

[Belegedhel]

I can't imagine that the black tank vent would, by conscious design, simply end in the interior of the wall, but not be vented outside.

It soulds like your interior skins are still in place--how do you know that your black tank vent pipe does not make it outside (other than the stink)?

How many of those squarish vent tops do you have mounted on top of your trailer (see the pic below)?

[Lumatic]

In my 71 the vent pipe runs inside a closet up to the roof, not between the wall.

[89Excella]

In my '89 Excella, mid bath, the black tank had a separate vent that ran up in the corner inside the bath. During the renovation I cut it , ran it through the wall into the refrigerator compartment and teed it into the plumbing vent line which was already there. Then I blocked off the old black went on the roof. It works fine this way and I reclaimed that bit of space in the corner. AS probably did not want to do this when it was built (maybe violates some RV builder's code) but it vent lines in houses are all done this way.
Maybe you could do the same thing if you have access to the plumbing vent line. You didn't.mention if there was evidence of a former vent cap on the roof. It's possible the two lines were tied together at one point but a PO may have changed to the current setup.
Good luck with your project!
Ed

[Jacob D]

Originally Posted by bwhitaker

So does anyone know if the 1971 overlander had the vent for the blackwater tank leaving the airstream? My open end is into the space between the aluminum shell and the interior lining. This was never a problem until today when the temperature got to over 80°F. There is nothing in the black tank either (waste). Now the inside smells like you could imagine...

My '67 Overlander black tank is vented thru the roof. I can't imagine any factory design would not vent the black tank to the outside somehow. Maybe this was an original production mistake or a change by a prev. owner.

[Silvertwinkie]

FWIW, my '04 has a black tank vent...and is one of the reasons I don't have reversible fantastic fans.



Grey water generating locations in the trailer have under fixture vents that draw air in, but don't let it go the other way. If the tank gets pressure due to heat, the 'P' traps will release some, if any built up gas, but the real need is a black vent stack as there are no under fixture vents for that.


Could you do without a black tank vent? Prob, but my guess is that the trailer around the toilet may get a bit unpleasant smelling....additives or not.