Still in need of help PLEASE Gray Tank

[tinkerreknit]

Originally Posted by Lrakeahs

Sorry about the quality, it was much better on my end....and the commercial, not sure where that came from....

Wow, I didn't realize those cameras were that long! So, the vent pipe extends 1/3 of the way down into the tank. The tank fills up to that point, and the ability to drain slows down as air is compressed in the tank and the vent pipe is submerged.
But it seems to me that if that's the problem the tank might drain very slowly for the first 1/3 of the tank, and below that, the vent could supply air to the tank and the discharge would speed up to normal flow. But you indicate that's not the case when emptying the tank.
I'm only trying to help, but I might be missing something.

[Bilgerat]

I have read your post, I did not see a response from you that the plumbing vent had been checked. I understand you have checked the roof vent, but have you looked under the counter where your sinks are? In my old MH I have 3 vents; 1 in the cabinet where the kitchen sink is, 1 in the cabinet where the bathroom wash basin is, and 1 in the cabinet where the washer/dryer would be installed. If you are not sure what one of these vents may look like, go on Amazon and search for, "plumbing vent". They are installed on the section of drain pipe that exits your cabinet, it is a Tee Fitting, with a straight pipe going up with the vent cap at the top (it allows air flow into your drain system).. I don't see how that would effect dumping your grey tank, but I am not an expert.

If you have checked that, I recommend leveling your rig, then adjust the jacks so you have a "slight down hill run" towards the drain outlet. Repeat the step you did with the bucket and see if you get any any drainage.

As for the tank level lights, they can not be trusted, food bits, grease/oil builds up in the bottom of the tank trying to get to the grey tank drain, and collects onto the probes when the tank has water in it on the inside of the tank.
Grease/oil floats on water and sticks to the sides of the tank and probes as the tank drains. I personally recommend not buying chemicals, additives. Most are probably not good for the environment, the septic system or your tank and valve seals.
I feel the best things to use to clean your waste tanks are; Dawn, vinegar, baking soda. I also like Happycamper, strictly my opinion.

I also Googled your year, make and model, seems there are a lot of quality control issues with the builder, I would suspect you may have something in your tank.
I will keep an ear out for you, hope whatever the problem, you can find the remedy. Good Luck.

[Lrakeahs]

Would this be the vent cap you are referring to? If so we have one under the kitchen sink and one under bathroom sink.... We removed and checked both... Couldn't see anything that looked wrong.....sorry pic is sideways....

We are still out here working through everyone's advice....

[Lrakeahs]

Ok so here's inside the tank....the furthest tube is the bathroom sink...the other 2 closest to the opening are the vent which the tub drains into, it's the one furthest from the opening...the other tube is the kitchen sink.....there are 2 things on the top of the gray tank ceiling, not sure if you can see them ,
wondering if those are sensors, or 1 is the sensor and one something else...

Oh my, we are so confused... It seems like such a simple system to be giving us such trouble....

[Lrakeahs]

Can't see anything that looks wonky... The pipes are the same distance so it doesn't look like one slipped down....

[cruzbill]

Wow, color video of the inner workings of a grey water tank-technology, what is next? Actually, the video is very informative. Now, I'll take a shot. The 'board' incident hit the grey drain and 'bent' it upwards, that's why the drain valve is 'bent' upwards, and at the same time, the drain pipe to which the valve is attached pushed upwards and that is why you have a 'dimple' on the top side of your grey tank. Check to see if your grey tank was actually lifted upwards by the force of the board. The road (drain) side of the tank has to be lower than the curb side for water to drain from the tank, usually this angle is achieved by the slope of the bottom of the tank, but if the road side of the tank has been lifted upwards by the 'board' accident, there may not be enough slope to the tank for it to drain fully. So you would have to look for some indication that the road side of the tank has been pushed up. It wouldn't take much to cause the slow drain you talk about. the video shows no issue with the vent, and the two pipes at the top of the tank, sink and shower, look fine. Check the slope of the tank bottom. And let us know!

[Bilgerat]

Yes those are your plumbing vents, so to be clear, you have confirmed that all your air vents are operating; inside the cabinets and roof vent are not an issue.

You do have standing water in your grey tank. Have you tilted your rig so there is a down hill run to the drain opening?

[cruzbill]

Bilgerat has a good idea, tilt the RV toward the drain and see if the grey tank empties all the way, if so, I think the tank has been pushed up by the 'board'.
If you could look at the end view of the tank, you'll find it has a 't'shape, as its designed to sit on two metal bars that go the full width of your motorhome. The tank sits in this metal frame, and the arms of the 't' are what keeps the tank from falling thru the frame to the ground (good thing). Check the road side of the tank to see if the leg of the 't' part of the tank is sitting flush on the metal support frame.

[Lrakeahs]

As a note...hubby was able to fix the depression yesterday in the gray tank box and the pipe leading out is all back where it should be..we refilled the tank and same results...could only fill 2/3rds full before it backed up.. The gray tank is totally empty.....so it is not retaining water..

[Lrakeahs]

So hubby was just saying....there are 2 things on the inside ceiling if the gray tank....you can see them in the photo that shows the very far tube from the bathroom sink...he is wondering are those the sensors, or could one be an overflow valve and that was damaged in the incident and should be allowing air in that way too....., Like does the 1st 20 gallons come up to the end of the pipes then there's still room for the other 16 gallons, and there's a small valve on the ceiling of the gray tank that allows air...or is the air strictly coming from the vent that goes up to the roof?

Sorry, working outside and from my cell... Sorry for typos... Will review all the information provided again in just a bit..

Have I said thank you for all your help.. Because I really do appreciate how awesome and helpful everyone is here.... I'd go crazy without you guys!

[cruzbill]

Take some leveling boards and put them under the curb side tires, run the MH up on the boards (two boards should do it) and see if the tank drains. If it does, look to see if the accident pushed up the road side of the tank. Forget about the vents, they work fine, its a simple system, no fancy check valves or overflow vents or anything else.

[cruzbill]

The tank level sensors are just a screw with a wire on it, you can see the screw heads and the wires in your picture of the end of the tank and 'bent' valve. Nothing fancy, nothing wrong with the sensors.

[Lrakeahs]

The gray tank is totally empty...not a stitch of water in it....

Oh, ok..I did see that wire... Wondered if it was the sensor...

What are the 2 things you see in the ceiling of the gray tank.. They are small things hanging down from the ceiling... about 2 feet from each other near middle of tank ceiling?

[cruzbill]

I can't see what you are referring to, but the only things that will penetrate a grey tank are drains for shower, sinks and vent pipe. Oh, and the drain on the side. That's it, nothing else. I'm confused, you say the grey tank doesn't hold water, that its empty, but then you say when you add water, you can only add 20 gal and then the shower drain backs up? Does the shower drain back up when you are hooked up to a sewer and you have the grey dump valve open?