Waste Holding Tank - '79 ODay 28

[Apex]

So I have replaced the Jabsco check valve, but still want to improve the overall system, lowering the tank. It appears the previous owner put the wast holding tank in the v-berth using both storage areas and blocking in the filler cushion area for the tank. It sits quite a bit higher than the head resulting in a lot of plumbing contents exerting pressure on the valve.

Anyone have other installations they really like? Anyone know of a tank source with a curved bottom so I can shift to one side, and regain the little bit of room in the v-berth/head ?

 

[Erieau]

Intuitively, it seems like the holding tank is "exerting pressure" on your head's joker valve because the tank is too high.
However, consider the head discharge line: it travels UP, to the TOP of the holding tank, where the goodies then drop down into the tank. Therefore, the only pressure acting upon your joker valve is the contents of the discharge hose.
Of the joker valves I've replaced, only one in three holds a reliable seal. Meaning, buy three and only one will hold back the contents of the discharge hose.
In other words, replace your joker valve. That's your backflow problem.

As to regaining storage space with a different holding tank, I can't help you there.

Best of luck.

 

[Apex]

yes, I agree. If the holding tank top is lower, that pressure (and distance ....thus volume....) is lower as well. We replaced the joker valve and so far so good. the old looked in decent condition, so visual inspection appears to be not useful.

Does anyone have the oringal holding tank configuration? This is clearly a modification. And are there any downfalls to the oem setup that this modification was trying to correct?