Re: blackwater tank leak
I had a greywater tank leak earlier this summer. It was actually in the drain piping. The hot coolant line for my flat plate heater had melted the ABS drain pipe. Although it was a little hard to access, the fix was an easy one: cut out damaged pipe and replace with new. It was common 1 1/2" black ABS found at plumbing or hardware stores. I moved the hot coolant line so I wouldn't experience a repeat.
Hope this might help you or others with similar problems. Good luck...
'04 EB-350 6.0 PSD SMB 4x4, PH, EB-50, Aluminess F/R