How is Toilet to Black Tank put together

[DC8Captain]

I have a question about what I'm seeing when I look down the toilet into the black tank. I'm sure that will get the jokers going. Anyway I see the end of the pipe that goes down into/to the black tank. My tank is suppose to hold 39 Gal.. When I put 25 gallons in through the sprayer the water is just at the bottom of the pipe and my lights show full. So does that pipe stick down into the tank thus giving me move volume to fill it up or is the water being at the bottom of the pipe signify that the tank is full. It seems that either the tank has more volume than the bottom of the pipe or the lights are correct and I have a 25 gal tank when I should have a 39 gal.. It would be nice to know where reality is.

Jayco support says they don't know and CW service adviser says he doesn't know and won't pull a tech off a job for a 3 minute conversation.

Dale

[Grumpy]

From what I have seen before, yes the pipe sticks below the top of the tank. Easy way to check, bend a coat hangar into a hook (6-8 inches long) put it down the pipe and pull up. How much goes up past the outside of the pipe?

[joe in calif]

As for the lights, they are mostly never right. Mine will come on FULL and I still have a lot of room left in the tank. Even when I drain it, it shows 1/3 . The sensors are activated bu moisture, once my trailer sits in the sun for a few days and the sensors dry out they will read empty.