Black tank leak issue

[74vette]

2012 3100RL I have been chasing a black tank leak when tank is almost full. After removing the underside I think I have found the issue. The tank seems to be two piece. A contoured bottom and a flat top. The leak is coming from the seam in the front of the tank just above the flush hose inlet. Has anyone dropped the black tank on one of these. Any input is appreciated. I might try drying and using a abs cement

[Carl n Susan]

That is a common point of failure on the 2 part tanks. Do a Search to see what others have done. You will probably wind up dropping the tank.

[twindman]

I think a lot of people with this problem have used some sort of epoxy or such to patch it.
By the way, I was having a leak 7-8 years ago in the same area. Turned out the hose connecting the back flush was not screwed in properly. Might check that out first.

[Cat320]

I fixed a black tank leak with JB Weld.

[74vette]

Update
I cleaned the area of the two piece tank (the front center) with brake clean. I then took ABS cement and pushed the cement into the area where the top meets the bottom of the tank. After letting cement dry, I used black Eterna Bond tape and covered the seam. After the next day I filled the tank and, No leaks. Even using the tank flush on full tank, no leaks. Not sure how long it will last but better than dropping the tank.

[Mikendebbie]

Good to hear and thanks for the update.

[beeje]

Number one if your unit is sitting level while you're using it should never get full enough to leak at that seam. If it is it's being overfilled probably what caused the problem.
Number two you should never travel with anything in any of the waste tanks with the exception of just going to the dump station.
I have not had mine out but I know how they come out because I've been all up and around that area.
The tank sits on two rails with one of the Rails removable.
I suppose if I was going to try and repair it I would have to have it out and see exactly what is leaking and how bad

[mtibbet]

The tank is made of black PVC. My tank split at the top and I repaired it with black pvc glue from the hardware store. I also glued a strip of pvc on top of the crack to reinforce it. That has been 3 years now with no problems

[ToolMan]

No matter how you go about the repair it will help to find a way to support the bottom of the tank. The tank manufacturer says the tank must have supports at the bottom not just supported by the rim. I had to replace our galley tank and used 2" wide nylon strapping to loop under the tank and over the frame members.

[rohrmann]

Originally Posted by mtibbet

The tank is made of black PVC. My tank split at the top and I repaired it with black pvc glue from the hardware store. I also glued a strip of pvc on top of the crack to reinforce it. That has been 3 years now with no problems

No, not PVC. The tanks prior to when they changed to the rotomold style of tank were all ABS, and ABS glue is what is used on ABS plumbing pipe and fitings.

[beeje]

Originally Posted by rohrmann

No, not PVC. The tanks prior to when they changed to the rotomold style of tank were all ABS, and ABS glue is what is used on ABS plumbing pipe and fitings.

Bob, there is also a all purpose glue that can be used on all abs/pvc/cpvc pipe. Its in a can with red color on it, (from oatey). I have been using it for many years with no issues (even without primer). Joints glued 20+ years ago in my pvc/abs drain lines and cpvc water lines still going strong with no leaks or failures.

[Mark7]

I had cracks in the top of my two-piece tanks. Both the front black and gray tanks. The cracks were too big to fix so I ended up replacing the tanks.

I agree with those who have said you should never travel with a lot of waste in those tanks. The flange were the lid is glued on cannot support that kind of weight bouncing down the road.

My galley tank also had a crack, but it was not nearly as large. I fix that by mixing some ABS cement up with some filings I produced by grinding up part of a black ABS fitting making a paste. After etching the tank I spread the paste on the crack. So far, so good.

Good luck with you’re repair.