Water leaking from Coroplast when Gray tank is full

[Dennyha]

For the second time, this weekend, I've experienced water leaking out of the front of the coroplast, and I've tied it to a full gray tank. I guess I expected a full gray tank (#1) to show up as water backed up in the shower. I didn't expect it to leak into the coroplast. Is this normal? Do I need to drop the coroplast and fix something?

 

[aRAYwego]

I had the same issue under warranty and it was a loose vent connection at the tank. They had to drop the coroplast to repair. Didn't take the dealership long.

 

[Dennyha]

First, I have to apologize for these pictures. For some reason, they all loaded sideways, and I don't know how to fix them.

Tonight, I decided to drop the coroplast from the front of the fiver, and see what is going on. After pulling the coroplast, I started filling the gray tank. After putting about 40 gallons into the tank, it started leaking from the front, driver's side of the unit.
When I looked inside the frame, I saw this.

As you can see, there was a hole on the top edge of the tank that spouted water when the tank filled up. The hole was probably there from new, as I can see how a tank can develop a crack, but I can't see how it grows a hole like this. Anyway, I made a trip to the hardware store and bought this.

After draining some water from the tank, I wiped the area with alcohol to clean it. Then, I mixed up some epoxy and applied it.


I'll let it cure tonight, and I'll test it out tomorrow, but I'm confidant that it's fixed.