May have broken my T@B S320 Boondock cassette

CandJB

I'm although I've had my T@B a while, I only had two outings before I needed to take a long break due to medical reasons. So, I very much consider myself a noob.

My first outing in years, my wife noticed that the bowl of the toilet had some backwash in it. I guess I didn't get it totally cleaned out time I emptied and rinsed it. I just assumed it was a case of that and didn't think any more about it.

This past weekend, when I started the process to dump the cassette, I noticed that the toilet trap (or whatever the sealing part is from the toilet seat into the cassette is called) would only close about half way. It had only been used 3 times for urination only, thank goodness, but there was a bit of an aroma.

When I pulled the tank out, my noobself forgot to use the release lever under the handle. I couldn't remember how hard it was to pull out, so I just tugged on it until it came out. In the process, I also caused the storage cover to pop off and who knows what else.

After dumping and rinsing it, I looked more closely at the trap in the cassette. It still was closing only half way. I decided to put it back in and contact my dealer when I got back home. I couldn't get the storage cover to stay put when I tried to pop it back on, and I can't get the cassette back in (with our without the storage cover). I'm afraid to force it for fear of breaking something else.

Is the lack of being able to close the trap indicative of a particular problem and could it also explain why I had trouble pulling it out and why it won't go back in now?

MuttonChops

Disclaimer: No direct Thetford Cassette knowledge.

Have you completed a youtube search?
While there are several models of the Thetford Cassette, the various youtube 'repair' videos might help you understand the mechanism and find a root cause/solution.

This Video For Example

CandJB

I have watched several. There are plenty for the C400, but mine is a C301. I don’t know the difference, but they look very, very similar, but not an exact match. I’ll look more closely at mine to compare with the video you linked. If I can remove that part, it might show me why the mechanism isn’t sealing. It doesn’t appear to have a single piece trap cover like in the video, but maybe the mechanism is working improperly such that it looks quite a bit different.

CandJB

That video helped. The take apart looks the same except my float came out from the other direction. My problem… the orginal one, I have more now, was that the trap disk that is supposed to seal had somehow come off track from the mechanism that opens and closes it. What I was seeing not sealing was not the trap disk, but the mechanism intended to open and close it.

I’ve got that back on track. Now I need to figure out how to reattach the float which came apart when I got the trap back in place.

I’m still reluctant to put it back into the trailer housing for it for fear of breaking something if I force it in.

I have an appointment with my dealer next week to check it all out.

I’m sure it will be classified as noob user error. 🤔😛

CandJB

SposhMeGosh! I may have fixed it! I’ve got my storage lid back in place, double checked the tank seal was working, made sure the toilet was set for being closed, and now things are back together.

Now I’m going to hook up to my home water (with pressure regulator) and power (gotta have AC since heat index is over 100F) and play with my toilet to check things out.

Amazing what a little toilet training can accomplish. Thanks @MuttonChops !

MuttonChops

@CandJB said: . . . mine is a C301.

Are you sure about that?

[black tank} Toilets seem to be the 30n series while cassette systems appear to be 20n and 40n in the Thetford product numbers, based on their catalogs.

All nüCamp cassettes "appear" to be some version of the c40n series.

CandJB

You're correct. When I do a search on the numbers on the tank (SKU,Model designation, and S/N) it comes up with a C403L.

I'll be doing a deep clean on it today and checking everything out. As far as I know at the moment, the only thing not right is the cover for the storage area. It's got a curve to it that may cause it to pop off when I remove the cassette. As long as it doesn't cause anything to hang, I'm OK with having to put it back on every time.

mx4789

Just a thought… the sliding "cover" for the storage area has a very faint arrow on it and the cassette body has a matching arrow. Make sure that the cover is slid in so that the two arrows are on the same side. It is possible to get that cover reversed and that will cause problems. The cover should slide back and open up when the cassette is inserted into the camper. Likewise, it closes when the cassette is removed. If it is placed on the cassette body backwards it can't function properly.

Not sure if that is your issue, but it is something to double check. I do wish they'd make those imprinted arrows a bit more noticeable since I have to verify mine every time I remove it for emptying/cleaning.

CandJB

I do think I had it on backwards. I hadn’t noticed those arrows until after watching a repair video that pointed them out. After I got the sealing disk back in place, I’ve been more careful about matching arrows on things and my problems seem to be resolved other than needing to help the storage lid stay in place when I start to slide the cassette back in.

The cassette is sliding in and out easily now and no longer feeling like it’s stuck on something.