Leaking gray water tank

[the thing]

2017 Coachman Pursuit, 27KB.
Does anyone know if there is an 'overflow' opening of some sort, on the gray tank ? When our indicator says our tank is +/- 2 thirds full, it starts leaking into the lower compartment on the passenger side. Thanks for any thoughts.

[5picker]

I have personally never seen a gray tank overflow in 40+ years..

I have seen tanks where the vent pipe wasn't sealed at the tank and caused a leak when full.

[HappyTrav]

I suspect that the indicator isn’t working properly and the tank is full.

Has it ever showed full? If it as never indicated full there is probably a wiring issue with that individual sensor.

Bob

[the thing]

Thank you. Maybe that's where I'll try to start investigating. There's not much room between the top of the tank and the underside of the floor but I'll see what I can find.

[the thing]

Thanks Bob. It seems like it starts leaking when the indicator is flickering between two thirds and full. I'm under the impression that the gray tank needs to be full before dumping the black tank. Maybe I need to pay more attention to how full the gray tank is.

[HappyTrav]

Originally Posted by the thing

Thank you. Maybe that's where I'll try to start investigating. There's not much room between the top of the tank and the underside of the floor but I'll see what I can find.

There are three sensors in the side of the tank. One for 1/3, 2/3, and full. When the tank is full it will overflow in the shower as it is the lowest point.

Before I started taking anything apart I would fill the grey tank and see if it ever shows full.

Bob

[5picker]

Originally Posted by the thing

Thanks Bob. It seems like it starts leaking when the indicator is flickering between two thirds and full. I'm under the impression that the gray tank needs to be full before dumping the black tank. Maybe I need to pay more attention to how full the gray tank is.

No, the grey tank doesn't need to be full before dumping the black tank.

Most recommend there be 'some' in the grey tank to use to flush the hose and connections after dumping the black tank but it certainly does not need to be full.

Keep in mind the 2/3 sensor will show 2/3 right up to the moment the tank gets full. There may not be anything wrong with your sensors.

[HappyTrav]

Originally Posted by the thing

Thanks Bob. It seems like it starts leaking when the indicator is flickering between two thirds and full. I'm under the impression that the gray tank needs to be full before dumping the black tank. Maybe I need to pay more attention to how full the gray tank is.

It just sounds like the sensor is off. I’m general they are notoriously inaccurate.


It doesn’t need to be full. You just want to be able to rinse out your sewer hose after dumping the black tank.

I leave my grey dump valve open until the night before we leave. Then I close it and the morning showers are sufficient to rinse the sewer hose and fittings

[Larry-NC]

Originally Posted by HappyTrav

It just sounds like the sensor is off. I’m general they are notoriously inaccurate.

You can define it a little more closely than that.

One common source of error is level of the RV. These sensors are mounted in a wall of the tank. If the RV is parked with that side of the tank down, the tank will indicate fuller than it is. If it's the high side, it will indicate lower. It is possible to make an indicator which is independent of tank orientation, but the sensor has to be mounted in the center (side-to-side and fore-and-aft) of the tank. Nobody does this.

The indicator might indicate that the tank is emptier than it is, if a wire from one of the sensors fell off. This is rare, and if it were any but the highest sensor, there would only be a gap in measurements; i.e., jumping from botto two lights on to the bottom two plus the top one, with third light out.

The notorious problem is indicating that the tank is fuller than it is. The sensors are measuring the low current conducted by waste water when they are submerged by it. If damp paper or humid salty waste is on the sensor, the same current could flow, even if not submerged.

Larry

[RJHuser]

Y’all need to read the OP’s original comment again!
He says the water is leaking into the lower compartment, not out of the shower drain.
There is NO overflow on a gray (or black) tank. These tanks have an inlet connection, a vent connection, and a discharge connection.
If water is coming out of anywhere except the discharge connection, there is a BIG problem. A cracked tank or a inlet or vent connection leaking/not connected.
There have been several reports of the vent or inlet pipe has pulled out of the tank (it’s generally a slip joint).
You, or your dealer, is going to have pull the bottom cover and inspect where the water is coming from. The tank may have be dropped to find/repair the problem.

Rick

[5picker]

Originally Posted by RJHuser

Y’all need to read the OP’s original comment again!
He says the water is leaking into the lower compartment, not out of the shower drain.
There is NO overflow on a gray (or black) tank. These tanks have an inlet connection, a vent connection, and a discharge connection.
If water is coming out of anywhere except the discharge connection, there is a BIG problem. A cracked tank or a inlet or vent connection leaking/not connected.
There have been several reports of the vent or inlet pipe has pulled out of the tank (it’s generally a slip joint).
You, or your dealer, is going to have pull the bottom cover and inspect where the water is coming from. The tank may have be dropped to find/repair the problem.

Rick

I guess you didn't read my post # 2.

[RJHuser]

Originally Posted by 5picker

I guess you didn't read my post # 2.

No, I read it, I was replying the OP in post #1.

Rick

[Witch Doctor]

I have a coachmen, don’t trust the lights, the best way has been posted. If your tank is full and your shower or sink is on it , it will not drain, you can tell if they hold water the shower is best being lower. If it’s filling up your vent pipe might be the problem at the collar. When you see it leaking run water in the shower and see if it drains if not it is full and coming out the vent collar. Don’t trust the idiot lights. It happened to mind but I learned how to deal with it. Hope this helps