Toilet to black tank pipe?

I relocated my toilet drain to the edge of a sloped black tank. Since I wanted excellent "slidage" with the deposits, I poured liquid wax down the drain, into the tank. Any furniture polish like Pledge will probably afford the same slippery surface to a plastic tank.

FWIW, my drain was connected to the tank with a pipe grommet. I used the same type grommet for the new location and stubbed off the original hole with threaded pipe cap and a new drain pipe.

I have an open underbelly so I know my tank is a rectangle running the width of the trailer and 12 to 18 inches tall. Both the black and gray tanks are the same tank.

I just purchased a cheap bore scope camera that hooks into my phone so before I do anything I will run it down the hole and have a look around.

I might just do the stainless steel rod idea and keep a piece handy for the times I need to use it. It would be better then hunting around the woods for a suitable stick and hoping it doesn't break off inside the tank.

Holding tanks come in a lot of different dimensions and shapes and in some cases the problem can be due to the tank being very shallow compared to it's width and length. I would assume you have an enclosed underbelly so you can't see the tank without taking down the coroplast, which is no easy task. If you happened to have a tank something like in the photo, I have to guess that could be a problem for blockage and flushing. Expecting 15 days on a tank seems a bit optimistic, esp. if not using plenty of water initially and at each flush of p**.

I would take a wire coat hanger and bend a "J" shaped in the end of it with maybe a 3" +/- hook (rise) on it. Put it down the pipe and push the short "hook" off to one side and see how far vertically you can pull it back up. This way you should be able to tell how far the pipe goes into the tank. An in-pipe USB snake camera is another option - available on ebay for cheap.

Some tanks have a flange screwed into place but it seems most are glued. If the pipe does go down too far, maybe a Dremel tool with a cutoff blade could be used to trim some of the ABS away (after pulling toilet). You wouldn't want the piece(s) cut off to fall into the tank tho. I tried to get the flange & pipe out of a previous TT and it wouldn't budge.

If you need to do a deep cleaning to get back to factory fresh condition, liquid Drano can be used. Our owner's manual says to use it. Use the version that does not attack metal. Just don't dump it into an on-site septic system. Add some before you head home and let it all slosh around, them find a dump station or dump at home.

One thing that helps a bunch, is to throw all "P" paper in a separate waste can, mainly if a woman is involved. For some reason, all women use an incredible amount of "P" paper. No no no, please don't donate any reasons !
Come to find out, many rv'ers (talking serious campers, not power pole huggers) thro "all" paper in separate waste can,......ka ka !! I couldn't handle that !!

The way you describe it, sure sounds like they used a flange pipe that's too long. It may be as easy as pulling the toilet, remove screws from the toilet flange pipe pull it out and cut..re-assemble... new toilet seal of course..

Thanks for the info RJsfishin, Joe417 and anyone else with useful information.

My tank doesn't have a pile under the spout, I start out with a few gallons in the tank after I dump, theirs plenty of water in tank to slosh when traveling and tank is filled before I dump and I rinse it good. Problem is not dumping and cleaning the tank problem is stuff getting stuck at the end of the pipe between tank bottom and pipe end. Sure I could use a ton more water then I already do when flushing but 100 gallons of fresh and a 50 gallon black tank isn't a lot of water holding capacity when dry camping for 15 days.

I would rather chance getting a pile of stuff under the spout that I could push free easier then trying to move the stuff that gets stuck between the tank bottom and pipe now. My thinking is if I shortened the pipe and started to get a cone of stuff a couple bowel fulls of water landing on top of it would break it up, right now all a bowl full of water does is plug up the pipe.

Some of my issue this time might have been a dry tank since I completely drained my holding tanks and reworked the dump line. The old hook up was a good 3 feet under the trailer and I hated having to get on my knees in who knows what the last dumpers left on the ground to remove the cap and hook up the drain hose so I removed the old pluming and reworked it so my cap now sets at the edge of the trailer and I can reach it standing up. About half way through the first day camping I remembered that my tank was dry and added a few bowl fulls of water to the holding tank but I'm sure it wasn't as much as I usually run with. Although this isn't the first time this has happened.

I'm in the more water camp. More water when flushing. More water when dumping. And add water back in after you dump. A few gallons of water sloshing around in there while driving down the road should loosen up the pile. Or, once you get it cleaned out, keep the pile from getting hard under the toilet to begin with.

I would trade off my TT before I would even think about messing with the black tank

In answer to your question, depends on the manufacturer. Some are glued and some are spin welded. Some plumbing is installed through a tight fitting grommet but I don't believe I've seen the toilet flange with just a rubber grommet.

Since it's a straight drop to the tank, a pressurized water jet should knock it loose and you can get a right angled nozzle. May take soaking and multiple cleanings.

Like some of the previous posts, sounds like the liquid is leaving the tank without the solids. This allows them to dry, stick, and build up.

Once you get it broken loose and cleaned, keep liquid in the tank at all times. I have a long drop from the tank to the valve so I put about 4 gallons in after draining and add chemicals. Only open the valve to drain the tank and if your tank has little in it, add water and then drain. That should keep the solids flushed out.

Some on here say they pour a lot of ice down the toilet and then drive around to clean the tank. Not sure that works but I would think that the residue in the tank would need to be softened up or the ice would just slide around and over it.

Most toilets drop right into the tank. No pipe.