Forum Discussion

ssthrd's avatar
ssthrd
Explorer
Apr 07, 2021

Grey tank connections

Anyone know if inlet/outlet pipe connections on a grey tank are glue on slips, or bell and spigot with a gasket, or maybe a repair type coupling.

I have narrowed my leak location down to the top of the tank, and I'm trying to get a handle on a plan of attack.
  • Our tanks are supported by a flange in a like manner. But the manufacturer went a step further by adding several supporting straps under the tanks and attached to the frame. Strongly suggest the addition of the supporting straps.

    Ken
  • Found the leak! My grey tanks are ABS, and have a 2" flange all around the top. Both sides are supported by a bracket which installs under the flange to hold everything up. My guess is when the tank was full, the weight was too much for the ABS flange which deflected enough to crack the tank just below.

    It was the first time that the tank was full since we bought the trailer last fall, so its hard to say if it has always been like that. In any case, I dropped the tank this morning, filled it up on the ground to find the leak, and saw nothing. I got my DW to sit on the tank for weight, and I lifted the front left corner.......... and the crack opened up and leaked like a sieve. Stopped when I let it go.

    I gouged out the crack with a hot soldering iron which did a good job closing the it, and I filled the remaining channel with two part epoxy which is compatible with ABS. When I filled the tank again a couple of hours later, the leak was gone.

    I will empty it tomorrow and put a couple of straps across the it for more support and hope for the best! Hopefully they will take some load off the flanges.

    Not a fun job, but better than paying a dealer way too much to do it. Sure glad it wasn't the black tank! I'm gonna put a couple of extra straps on it too since I have it open right now.
  • On mine the gray tank is a grommet with the pipe slip fit into it. I was having trouble with it leaking when it was full and discovered that it was not lining up correctly with the hole in the floor. This distorted the grommet so that it leaked when full. Enlarging the holed in the floor let the grommet return to its proper shape and it no longer leaks.
  • Thanks guys. Hoping for the rubber coupling. Should know tomorrow when I get back to it.
  • More than likely, the connection directly to the tank connection is a a slipped on rubber piece and clamped. The valves are bolted on with a flange,
    a gasket and 4 bolts clamping the assembly together.

    The gray tank should be a smaller 1.5 in pipe and the black a 3 in pipe. Some manufacturers install the tanks with the piping glued to the tank on out.

    Fitting
    This a 3" fitting, but available in 1.5"
    Ken
  • The gate valve on the outlet will have four bolts/nuts to remove. As for the inlet, your guess is as good as mine.