(Leak!) Toilet plumbing connection to Black Waste tank...
This question is regarding a 2015 Thor Majestic 28a (but I assume most Class C RVs are hooked up similarly)...
Summary: Leak at the toilet waste line connection to the top of the Black Waste Tank...
Recently my Class C RV was out on a trip with a friend. While parked at a campsite, the front brackets holding the black waste tank gave out (looks like there weren't enough bolts installed to begin with). This caused the black waste tank to "drop" just in the front (the rear brackets still held). Probably dropped 8-10 inches. It caused the front waste line connection that goes to the blade valve to become disconnected. My friend patched it together and got it home.
Here's what I did to fix things... I could see on the two front brackets that there were holes in each bracket for 3 short lag bolt/screws and that only 2 had been installed. The holes were still fairly intact. I got slightly larger screws and then felt like they grabbed really well (these are like lag bolts/screws that you tighten with a socket). Then I put in the 3rd screw and that felt like it grabbed very strongly as well. That probably would have been good enough, but I don't like to leave anything to chance. So I ordered a 3rd bracket and installed it as well. I feel good that the tank isn't going anywhere now.
I connected the 3" exit drain (to the blade valve) with a coupling and silicon. That seems to be rock solid now also.
Here's the problem: I did a water test. First I did a great flush of the black tank. (I recently installed a Tornado Flush that works very well). Then I started filling the tank with water from the toilet (5 Gallon buckets at a time). I could eventually hear that the black waste tank was getting full (and I could verify with my sensors). Finally, I could see/hear that the tank was full and the water was starting to not go down the toilet opening (black tank full). BUT, when I stopped pouring in water I could see that the water in the toilet tank did start draining and I could hear leaking/splashing water underneath the RV. Ugh! Apparently, where the toilet plumbing connects to the top of the black waste tank there is a leak. I guess that probably makes sense since the front of the black tank had fallen ~8-10 inches when the front brackets failed and that likely put stress on the connection to the toilet plumbing (which happens at the very rear of the black waste tank).
I could get just enough clearance to reach up there and feel around (with gloves on of course). I could feel the collar connection. I decided to take a chance and see if I could apply enough silicon caulking all around that collar connection and maybe I'd get lucky and it would seal it up. I tried...I failed...lol. Still leaks.
I did have a momentary thought: Maybe it isn't so bad??? If the black tank is full and about to come up the waste line into the toilet would it be better for it to actually leak out on the ground under the RV, OR eventually fill up the waste line to the toilet and then the toilet and then possibly overflow into the RV? Am I crazy for having this thought? (I think so, but maybe not). My sensors are good/working and for this RV I can always know that when the sensor says FULL don't add any more (and I can tell others who might be using this RV).
But I really don't like when things aren't "right/correct". So ultimately I know I'll want to fix this. Question: This is supposed to be a water-tight system so that your toilet fills up (and holds everything) in the event you fill up your waste tank and the plumbing to the toilet, right? Assuming that is the case, what is the correct process for fixing this? I can envision disconnecting the waste line to the blade valve and removing the brackets that are holding the tank up, BUT I'm struggling to understand how the connections on the top of the tank are made and in what order (from the toilet waste line and maybe there is one more from the bathroom sink).
Has anyone here tackled this project before and would care to share details?
Thanks!
Chris
UPDATE: See post #10 below on 5/15/22 for a full summary with photos of the fix...
Summary: Leak at the toilet waste line connection to the top of the Black Waste Tank...
Recently my Class C RV was out on a trip with a friend. While parked at a campsite, the front brackets holding the black waste tank gave out (looks like there weren't enough bolts installed to begin with). This caused the black waste tank to "drop" just in the front (the rear brackets still held). Probably dropped 8-10 inches. It caused the front waste line connection that goes to the blade valve to become disconnected. My friend patched it together and got it home.
Here's what I did to fix things... I could see on the two front brackets that there were holes in each bracket for 3 short lag bolt/screws and that only 2 had been installed. The holes were still fairly intact. I got slightly larger screws and then felt like they grabbed really well (these are like lag bolts/screws that you tighten with a socket). Then I put in the 3rd screw and that felt like it grabbed very strongly as well. That probably would have been good enough, but I don't like to leave anything to chance. So I ordered a 3rd bracket and installed it as well. I feel good that the tank isn't going anywhere now.
I connected the 3" exit drain (to the blade valve) with a coupling and silicon. That seems to be rock solid now also.
Here's the problem: I did a water test. First I did a great flush of the black tank. (I recently installed a Tornado Flush that works very well). Then I started filling the tank with water from the toilet (5 Gallon buckets at a time). I could eventually hear that the black waste tank was getting full (and I could verify with my sensors). Finally, I could see/hear that the tank was full and the water was starting to not go down the toilet opening (black tank full). BUT, when I stopped pouring in water I could see that the water in the toilet tank did start draining and I could hear leaking/splashing water underneath the RV. Ugh! Apparently, where the toilet plumbing connects to the top of the black waste tank there is a leak. I guess that probably makes sense since the front of the black tank had fallen ~8-10 inches when the front brackets failed and that likely put stress on the connection to the toilet plumbing (which happens at the very rear of the black waste tank).
I could get just enough clearance to reach up there and feel around (with gloves on of course). I could feel the collar connection. I decided to take a chance and see if I could apply enough silicon caulking all around that collar connection and maybe I'd get lucky and it would seal it up. I tried...I failed...lol. Still leaks.
I did have a momentary thought: Maybe it isn't so bad??? If the black tank is full and about to come up the waste line into the toilet would it be better for it to actually leak out on the ground under the RV, OR eventually fill up the waste line to the toilet and then the toilet and then possibly overflow into the RV? Am I crazy for having this thought? (I think so, but maybe not). My sensors are good/working and for this RV I can always know that when the sensor says FULL don't add any more (and I can tell others who might be using this RV).
But I really don't like when things aren't "right/correct". So ultimately I know I'll want to fix this. Question: This is supposed to be a water-tight system so that your toilet fills up (and holds everything) in the event you fill up your waste tank and the plumbing to the toilet, right? Assuming that is the case, what is the correct process for fixing this? I can envision disconnecting the waste line to the blade valve and removing the brackets that are holding the tank up, BUT I'm struggling to understand how the connections on the top of the tank are made and in what order (from the toilet waste line and maybe there is one more from the bathroom sink).
Has anyone here tackled this project before and would care to share details?
Thanks!
Chris
UPDATE: See post #10 below on 5/15/22 for a full summary with photos of the fix...
