Toilet to black tank pipe?

The pipe is glued into the toilet flange that screws to the floor, the same flange that captures the 2 bolts that holds the toilet down.
The pipe is glued to the flange, then pushed down thru a big rubber bushing that is mounted into a hole cut into the plastic tank.
It is very possible that the pipe is longer than it needs to be. It should protrude into the tank about 1 to 1 1/2 inches when the flange hits the floor. If its longer than that, remove the turlet, then remove the flange from the floor, then cut off the excess pipe. Replace the wax ring when reinstalling the turlet.
The pipe on mine is 6" long, and extends into the "brand new" 45 gallon tank about 1 inch, but problem is that the tank "at that point" is only 5 inches deep. So I still have a problem w/ buildup to the pipe now and then. I have a ss rod there just for breaking it up when need be,....not much of a problem really. Of course using more water mite help, but then I wouldn't be able to go 16 daya on a dump either.

Caution for info above,....this was the way the pipe installs in the tank on my Rexhaul Vision. But I am told others may be mounted differently

If your toilet sits above the black tank removing it and the flange pipe should be fairly easy. I just replaced my black tank recently (upgraded from 5gallon to 25) and it was a fairly simple process. However as others have noted the problem may not be the plumbing.

In my trailer the pipe is short.

RV toilet is rather imperfect system, solids may pile up in the tank and dry out there, before you empty the tank. Use more water.

Also sounds like you maybe are leaving your black tank valve open instead of letting the tank fill at least 2/3rd before you dump..??

Sorry, I have no help about how to remove the black tank plumbing...sounds like a rather involved job.

I've been where you're at. After having the tanks power washed we learned of our mistakes. Now, when it is time to dump the black tank, wife stands over the toilet with the trap open and I fill the tank from the outside with the tank rinser. When she sees water coming up from the bottom she knocks on the wall and I pull the handle. Woooosh! Repeat and then close up with 10 gal of fresh water and your done. Always flush a lot of water and bingo. No more problems. Geo method if you're so inclined and you should not have any more problems - we haven't.

If you have enough access to your tanks, you can do what we did which is cut a hole in the top of the tank and install a deck plate. Just search for deck plate on amazon. With the deck plate, we can give our tank a really good cleaning every so often.

this is a first Ive heard of this being a problem. Greyemunson makes a good point, this does sound like your people are not using enough water. We have everyone trained to fill the bowl with water for 30 seconds, which is about the same level as the home bowl, and let a 15 second chaser go down with the hard stuff...

Make sure everyone gets in the habit of filling the toilet bowl with water and giving a 'second flush' after using the toilet. The pipe going down into the tank is purposely long to make sure a bowlful of water disperses the solid material underneath it rather than just washing off to the sides of the pile. You MUST flush with water to keep RV black tanks working right. The extra bowl of water also makes sure when you dump, there is enough water moving toward the drain to carry the solid material with it.