Gray tank plugged, limited options

[CarArt]

Yes, I know it's been beaten to death but please bare with me.
70, disabled, on SS so on a budget. Not the issue, just sayin'. Yes, I'd love to have Joes RV Specialist come out but I need to try something on my own first.

My gray tank will not drain, says full, believe it since if I add water to kitchen sink it leaks onto the ground(?) from beneath RV(covered underbody so I can't see from where). I've endlessly searched the options but it seems with a full tank, not being able to move my RV out of the parking space, this creates some issues. Tried a snake, down the vent tube too. Not sure it gets where it needs to be because of turns in the plumbing. Thinking it's simply partially full of sludge since the valve seems to operate ok and I've replace the black one myself so I know what goes wrong. I'm fairly careful about what I let go down the sink but we all know sooner or later likely to have an issue. I have screens in my kitchen sink but I bought it used so...?

To the meat of my question-
I'm considering trying a variation on something I've seen but that I haven't really seen anything about specifically. And I've looked. Attaching a garden hose to the Clear 45 Degree Hose Adapter Sewer Fitting(Main), closing 2 valves on black and bathroom gray tanks, then opening garden hose attached to the adapter and letting water pressure go up to the blocked kitchen gray tank(this valve open) and "backwash" the plug, shut off then hopefully it will break free and flow out. Probably repeat.

Obvious issues-

1. too much water backwashing and shooting up and out kitchen sink/plumbing not intended to contain pressure. yuk. Plan to just open the garden hose, watch as it fills the Clear 45 Degree Hose Adapter Sewer Fitting, shut off- see if I get the release coming back out.
2. worried about breaking plumbing/tank but again will not just open garden hose and let it run. Open/close and look for release.

anyone try this? have any "no way!", "watch out for this", "glad we're not neighbors" "Genius!"

[riggsp]

Heard of a case like that a long time ago...When the factory drilled the tank for the pipe connections, they use a hole saw and the plug they cut out stayed in the tank...eventually that plastic disc made it’s way to the drain connection and acted like a cover over the inside of the drain and water pressure held it there...attach a short piece of sewer hose to keep the end above the tank and push a cleanout snake through with the valve open to push that disc out of the way...if the tank in full, water will run out the top around the pipe entrance if it doesn’t have a seal around it...that happened with mine.

[CarArt]

it's difficult to determine as this gray tank is not near the main sewer exit. All 3 come out as one and this tank is(again my underbody of RV is covered) maybe 6-8ft feet from exit. I'l again try a snake, then the hose water preesure and report back. I know it seems like a bad valve but just seeing if anyone has tried water pressure or thoughts on it.

[mnoeltne]

Have you tried pushing a snake or wire or something in from the bottom to verify 100% that the valve is opening?

I have no idea how yours is setup, but on mine I would only have to run the snake or wire in about 12" from where the drain hose connects. So, leave the hose off and see how much snake you can run up there compared to the distance to the gray valve.

[CarArt]

thanks guys. Appreciate all the suggestions even if looking for your thoughts on using water pressure to remove the clog with backwashing. I'll let you all know if my theory works or I'm sleeping with the sweet smell of gray water awash on my ceiling and floor. If the valve not opening, not a problem anyway. Still clogged.

[Dusty_R]

I'd try a snake, or maybe an electricians steel fish tape.
To keep the gray water off the ground and making a mess, put a drain hose on and keep the open end above the hight of the top of the gray tank.

[Old-Biscuit]

You have owned this RV for 10 yrs and no draining problems with grey tank until just recently......

Your grey dump valve is NOT opening

[Lwiddis]

“70, disabled, on SS so on a budget” is extraneous regarding anyone’s grey tank issues.

[firemedic1992]

I used Septobac

When my black tank got clogged this spring. I put in a package and let it sit for a few days and it worked great!

[MrWizard]

moved from Technology corner

[CarArt]

I've seen a guy advertise he'd comes out with a 4000 psi pump and essentially does the same thing. Similar to my idea using brut force vs water pressure build up

[CarArt]

yes, that's something I saw and affirmed the idea. It is possible but has the draw backs mentioned above. The fact my tank is full now is a problem and could easily cause a mess inside mentioned. Even if 3/4 full I could give it a shot of water for a few seconds knowing that wouldnt fill it but maybe enough to loosen the clog.

[Dick_B]

There is a back flush device on the market. Camping World calls it a Hydro Flush for $20.

[STBRetired]

Running water backwards into the tank might loosen the clog, but then it will start pushing water up your drains. Could make a huge mess if you aren't careful. Doesn't sound right that running water in the sink ends up on the ground. I would start with the camera and see what you can by running it up the drain connection. Then maybe make a small hole for the camera near where the water is coming out and try to see why that is happening. My grey tank has 3 connections. Waste in, waste out, and vent which goes through the roof. There is no place where it could overflow onto the ground unless I somehow pushed water up the vent and it ran out onto the roof.

[Son_of_Norway]

If your gray tank was full and plugged, the water would back up into your sink or shower stall, there would not be any leak from the bottom of the RV. The fact that it is leaking from the underbelly indicates that you have a leak.

[CarArt]

did try using a garden hose but wouldn't make the turns.