on a recent trip thru some of the southern states we were on some pretty rough Hiways and some washboard gravel roads. I noticed the black tank or pipelines had a small leak , well by the time we got home it is a pretty steady leak. Our last 2 nights on the road we limited the use of the toilet and left the valve open so that there would be nothing in the tank.At home we checked it out and it seems there is a collar in the black tank and another collar on the bottomside of the tank and if I try to push the sewer line around you can see the collars move around as if they are no longer sandwiched against the tank, if that is how they work. There are no clamps or anything. It looks like everthing is glued together until you get to the knife valve. I thought we might be able to squeeze some kind of caulking material between the bottom of the tank and the collar. Has anyone ever had this problem? What did you do? Does anyone have any suggestions or ideas about it? There isn't much room to work in.

It's heat welded together, unless its an ABS tank, at which point, ABS cement can be used to glue back together.If it's polypropeleyne, you'll need to melt it back together.Most likely, you'll need to drop the bottom of the camper and completely dismount the tank if it needs a heat weld repair.

If the tank and collar are abs the use abs plumbing cement. Hopefully there is good access. The c ollars could also be rubber, in which case a good automotive silicone should work.

They have ferncos ,not sure if this would help ,muffler clamps on both ends. If it would fix it without removing or welding might be worth a try.

Photos would help others help you.Wayne

This is a picture showing the plumbing under the tank. The tank is just a few inches directly above the floor.That different colored ring around the pipe on the bottom was sealed with silastic which I peeled away and removed the ring. You will see it doesnt allow much access.I will take more pictures tommorow. Thanks for looking and replying.

Black tank leaking | Good Sam Community

22 Replies

Farmerjon
Explorer
Nov 26, 2013
Thank you all for your feedback.
It has really been a help in letting me get a grasp on whats going on with my tank.And you have all thrown some good ideas out there. Thank you.

AnEv942
You are right on with what we have.
when I look at it from above there is no collar as I previously thought but instead there is a depression around the outlet hole and what I can see moving is the top part of that flange sticking thru the hole and maybe a 1/4 inch above the tank bottom.
There is no water left in that recession.
We will find out if the flang broke all the way loose from the tank or just a small area.
We are open to a small repair or if we have to we will replace both of the valves and the connecting plumbing.
The camper has been put away in the barn and our nights have been in the mid teens, so we won't be working on it untill we hit a warm stretch of weather.
Again thank you all very much.
Jon
time2roll
Nomad
Nov 24, 2013
Farmerjon wrote:
Yes the leak seems to be at the bottom of the tank where the pipe goes into the tank. I can wiggle the pipe assembly and get a lot of play where it goes into the tank. You can also see the movement from inside the tank.
No it's not leaking at the toilet connection. If I put even a small amount of water in the tank it immediatly starts dripping out.

I think I would be looking at cutting the pipe so that the fitting that is observed as moving can be removed and repaired.

If the fitting is glued on I recommend the Plasti-Mend product to repair the joint.
jimh406
Explorer III
Nov 24, 2013
I think this is going to be a big mess to do. I'd consider replacing the whole thing why I was at it if you are planning on keeping it for a while. I don't think the parts are that much, but of course, it depends on how much money you have whether it is worth taking a risk of the next component will break.
HMS_Beagle
Explorer
Nov 24, 2013
The valve bodies have four bolts holding them together. If you take them all out (black and grey) it looks like you could get that stuff out of the way, now you have only a stub dropping directly through your floor. Enlarge the hole in the floor a bit with either the cut off jig saw blade previously mentioned or a Fein type multitool oscillating blade saw. I would then try to remove the flange from the tank. The glue joint is already cracked, so by wiggling it you might be able to complete the job. Now you have good access to everything to clean it up, and re-glue it.

At this point if it were ME, I might try to get a rubber no-hub connector between the tank and valve. That is a very short run, and stiffened by the grey water pipe. So any flex between plumbing and tank has to be taken by the glued flange connection - which must have contributed to its early fatigue. A rubber no-hub would give you some flexibility there to accommodate movement.
handye9
Explorer II
Nov 23, 2013
Farmerjon wrote:

Handy9
What did you use to clean it?

Denatured alcohol
AnEv942
Nomad
Nov 23, 2013

Your last photo-if leaking at B would be easy-but sounds like at A.
Brighting the pic revels what appears to be a thin flange?
Curious you said you could see pipe wiggle from inside the tanks, you actually SEE the pipe? Is it flush inside?

This is what I believe you have

ABS holding tank flange or holding tank hub inlet. It is glued
To effectively repair you will need to remove. Hopefully its completely loose. Other than access problem I'm see is re-orientating, short of replacing everything aligning might be hardest part. You can buy replacement pieces. I might look at disconnecting the gray water line-splicing in at least one piece of flex coupling (hose with clamps). Worst case just put another dump valve-there are work arounds so Id focus on the tank flange.
Farmerjon
Explorer
Nov 23, 2013
Yes the leak seems to be at the bottom of the tank where the pipe goes into the tank. I can wiggle the pipe assembly and get a lot of play where it goes into the tank. You can also see the movement from inside the tank.
No it's not leaking at the toilet connection. If I put even a small amount of water in the tank it immediatly starts dripping out.
ticki2
Explorer
Nov 23, 2013
Farmerjon wrote:

I'm having trouble with connection and getting pictures to upload,but you can see I don't have much space to work in.
Handy9
What did you use to clean it?

It is still not clear exactly where the leak is . Is it at the bottom of the tank in this picture or is it in the pipe and valve on the outside ? Is it possible that is leaking from the top at the toilet connection . The black tank seems to indicate it is ABS plastic . That would be good as ABS is repairable with ABS cement .You can test with MEK to see if it dissolves the plastic . The white ring on the outside is not a seal , just decorative and to close up the hole from the elements . If not removing the tank you will have to at least do as Covered Wagon suggests and cut a larger access hole . From the picture I'm guessing that the 3" pipe going into the tank fitting is glued and not threaded .Good luck .
covered_wagon
Explorer
Nov 22, 2013
I would say most likely there are threads molded into the poly tank for a 3'' ABS male adapter to screw into the tank. In any case, use 5200 on any threaded parts. Better to get sealant in between parts rather than on top or outside like you would for most cosmetic caulking.
Farmerjon
Explorer
Nov 22, 2013
Sorry I wasn't clear about the pictures, it was confusing.
Thank you all for looking and your suggestions

I don't know how it connects to the tank.

Covered wagon. are you saying there are threads in the tank that the collars screw on to or is there a pipe clued onto the tank and threads on that?