Water coming from grey tank

[ltoews]

During this past summer, we had a small trickle of water from the grey tank (not the galley tank) running out from the underbelly. The water only leaked out when the tank was completely full. In over seven years with this Montana, we've occasionally had the tank so full that water started backing up into the shower and never had a leak underneath. I would like to know if the drain pipe from the shower and sink is cemented into the tank or is there a rubber grommet that the drain pipe goes through? A dealer’s service department says the drain pipe is just stuck into the tank. Do these tanks have a method to release water if completely full so they do not get too full and rupture? Has anyone ever had an experience like this?

[Eagleback]

Same issue i have right now. I lowered the belly and investigated. I thought it was a leak in the black tank flush, but not there and found after the grey tank got full to the top just Like your describing. it started leaking from on top but not from the drain pipes into the the tank. it has a crack somewhere on top and the only way to get to it is to drop the tank. I am debating if i want to do that as i full time and the grey tank is open about 95% of the time except when i dump the black every week.

[richfaa]

Originally Posted by ltoews

During this past summer, we had a small trickle of water from the grey tank (not the galley tank) running out from the underbelly. The water only leaked out when the tank was completely full. In over seven years with this Montana, we've occasionally had the tank so full that water started backing up into the shower and never had a leak underneath. I would like to know if the drain pipe from the shower and sink is cemented into the tank or is there a rubber grommet that the drain pipe goes through? A dealer’s service department says the drain pipe is just stuck into the tank. Do these tanks have a method to release water if completely full so they do not get too full and rupture? Has anyone ever had an experience like this?

On our 06 3400 and this 13 3402 the tank was glued into the top of the tank and they both failed at that point.Lesson learned do not let the tank, any tank fill up. Try just letting your tank fill half way then see if it leaks. The input drain will pull away from the input causing the leak when full then the weight of the liquid in the tank as it fills will will cause it to over flow at the point were it separated. You might get it 3/4 full and no leaks.

[mazboy]

If you have someone drop it make sure a replacement tank is available....

[leemedic]

Originally Posted by ltoews

During this past summer, we had a small trickle of water from the grey tank (not the galley tank) running out from the underbelly. The water only leaked out when the tank was completely full. In over seven years with this Montana, we've occasionally had the tank so full that water started backing up into the shower and never had a leak underneath. I would like to know if the drain pipe from the shower and sink is cemented into the tank or is there a rubber grommet that the drain pipe goes through? A dealer’s service department says the drain pipe is just stuck into the tank. Do these tanks have a method to release water if completely full so they do not get too full and rupture? Has anyone ever had an experience like this?

Been there, done that. Have rupture 2 grey tanks. If it overfills, it will backup into your RV.

[Chip]

Our galley tank is that way now. Hope to get it replaced this fall before our extended warranty runs out.