Black Tank Leak

westend wrote:
I would be thinking about securing the pipe with some good hangers. I thought most ABS drain pipes are solvent welded to the ABS tank. It sounds like you have a mix of materials.

Is it possible that you had a through-tank rubber seal on the pipe and the back half sheared off? Something like this:tank grommet

Thank you for the information and link to black tank supplies. You've got me thinking that it could be a broken grommet instead of what I thought it was. Got to wait for things to dry out and I can work with it and see what is what. If it is a rubber grommet, that's a hard piece of rubber.

There is an over flow of white cement from where the internal grommet is glued to the tank. Thought that it was the same cement used between the grommets.

I would be thinking about securing the pipe with some good hangers. I thought most ABS drain pipes are solvent welded to the ABS tank. It sounds like you have a mix of materials.

Is it possible that you had a through-tank rubber seal on the pipe and the back half sheared off? Something like this:tank grommet

So far as I can tell the grommet isn't broken, the cement between them has failed. Am considering disconnecting both black pipes at the valves and attempting to pull the black soil pipe out of the tank. That may/may not work depending on how far around the grommet the cement has failed. If that works, then I can clean both grommets and re-cement.

Why not just replace the broken grommet…

The tank leak discussed in the OP occurs between the white grommet installed inside the tank and another white one the black pipe is inserted in. During construction, the two grommets were pushed one inside the other at the tank wall, the tank outlet. The cement between the two grommets has failed. There is no leakage from the black pipe. I assume the stress of bouncing down the road and operation of the black tank valve are the causes. If you push on the black pipe you can open the gap between the grommets and increase the flow. Otherwise, it's a annoying, smelly drip.

The juncture of the two grommets is raised about 3/8" above the level of the black pipe and the space between the terminal lip on the inside grommet and flange edge on the outside grommet is about 1/8". This presents a rather narrow surface to seal. Once I get it sealed I have to secure the black pipe in such a way to avoid repeating the damage.

Not knowing the composition of the white plastic grommets is causing a problem in knowing what product(s) to use. Any suggestions?

Just fixed a crack in my blank tank last month with the above mentioned ABS repair kit from here. This product was awesome! The worse part of the repair was getting the tank cleaned out and then dried out for 2 weeks before I could apply Plasti-mend.

tvman44 wrote:
I think Eternabond tape would do the job permanently.

Could be tough using a roller around a pipe :B

Magic puddy

I think Eternabond tape would do the job permanently.

I used a marine epoxy to repair my swiming pool were the pump hose conects to the side of the pool. It looks like a puty stick, just break off a piece, nead it together with your hands and work it into the crack even while wet. I bought it at my local hardware store and it held up for a couple seasons.