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!"

[cephoto]

Exactly. Well not exactly but something very similar in mind. Using the clear elbow. But after listening to the responses and then doing a lot more research I’m thinking it may be as they’ve said above that it’s the valve. I went to YouTube and found very technical information from valve manufacturers that seem to describe my issue.
Since you’ve been kind enough to provide your thoughts, maybe I’ll pick your mind just a little further.
Solution # 2
As you say no solutions, especially replacing the valve with a full tank could spell disaster. So at this point I’m sure that I have to figure out a way to drain the tank in place, without spills before attempting the valve replacement. Problem.
Inside my RV I know where the tank vent comes up through the wall and I think I can easily gain access to it. I was thinking of cutting through the pipe several feet above the floor and then renting a pump, dropping the intake hose down into the full gray tank, the outlet hose into my toilet with the black tank valve open.
Opinion(s)?

Thanks regardless.

[theczar]

Seems like all the suggestions will result in a significant mess which the campground, you or your neighbors will not appreciate. I had a problem similar to yours only it was the black tank. Ugh! After thinking about it I came up with a device to use water pressure to clear the clog while still keeping the sewer connection hooked up. I decided on getting a clear sewer elbow, some pex, a hose connector and grommet. I drilled a hole in the elbow. Hooked up the pex to the hose adapter. Put the grommet in the drilled hole and inserted the pex.

Hooked up the device, connected the sewer hose to the end of this to the sewer hookup. Put a hose on the connector and you are ready to go. You can push the pex in or pull out through the grommet to fish the pex into the correct branch of the system. The pex being 3/8 inch restricted the flow so the water was like a jet and it broke up the blockage and all flowed through the system to the sewer with barely a drop of liquid spilled. Pressure will not build up in the system since water is allowed to drain

I will try to get you a picture when I’ get to the storage lot. Here are a couple links to some of the parts referenced above

https://www.walmart.com/ip/Camco-Rhinoflex-Swivels-90-Clear-Fitting-Odortight-Connection/23636867

https://www.homedepot.com/p/SharkBite-1-4-in-3-8-in-O-D-Brass-Push-to-Connect-x-3-4-in-Brass-Garden-...

Good luck

[Garciawaters]

Hello fellow RV'ers. First time utilizing Sony type of forum. I recently had the same issue. My galley grey tank was clogged with calcium, grease, food ect... after cutting the pipe under the tank and placing a double fitting problem solved. I am however, having a issue that continues to occur after that four order of a clog has been resolved. I had the carpet and padding pulled out and vinyl planking put in. I have a sludge like substance seeping up through the cracks in the planks. It hardens like tar and is so foul smelling. I clean it and it returns. This is actually how I discovered that I had a clog in the galley grey tank in the first place. After the clog was removed and the smell under my rid subsided, I am left with this sludge. I am very hesitant in removing the flooring to expose the wood underneath. Does anyone have any suggestions as to what to do. Or even what ot is. My fear is that the clog was there for years and it seeped through the wood floor causing mold and just plain garbage water to soak the wood. I should say I'm a first time rv owner and live in my fifthwheel year round. Also I'm a 48 year old woman who has fixed everything that has occurred myself. This one though seems a bit daunting. Help?????

[down_home]

Cal the factory. They made it with the two tanks exiting in one opening.
Ours is the same way. If black tank the toilet goes straight down into the tank.
The gray tank...its either the valve or a piece of something. Drains have screens so it is unlikely someone dropped something down it.
If you dump grease down the drain, over a long time you may have a lump of it blocking things up.
I'm not familiar with removing the drain valve but last resort you may have to.
If you can establish that the drain vale is open a snake may be inserted through that way and break things up. Just be careful not to damage valve
Leak? If you have a large puddle, on the ground, then there is the reason nothing is coming out the drain. It's liquid part, at least is, already out....unless you overfilled and gray water came up through the shower and out, or out the vent and ran down the side of the RV.

[CarArt]

thanks dougrainer. 3 tanks, 3 vents. Going to see whats up down there. I replaced the black tank valve and remembered doing something similar. Good info, thanks again. Lived in Carrolton myself.

[dougrainer]

There is no rule that states the 1.5 inch vent pipe has to go straight up from the tank to the roof. Even if there is a Y in the wall, you can probably snake a tube down to pump it out. IF you have 2 tanks and 2 roof vents, then no Y. IF you have 3 tanks and 3 vents no Y. BUT, they may have a slight ABS elbow going up, but that would still allow a snake hose to go into the tank. What I do when I suspect or verify a Valve has broken loose from the handle rod. I drill a 1/4 inch hole thru the center of the valve 180 degrees opposite of the original handle and then run a 1/4 steel rod into that hole and push the knife valve open. The 1/4 inch steel rod minimizes any leakage. You leave it partially in the drilled hole to seal, until the tank is empty. Then you have a empty tank when you replace the valve. Not sure if you stated, do you have a mechanical manual HANDLE or you have the Cable driven Dump Valve? If cable driven you can usually access the pull rod where the cable attaches at the valve and pull it open. Doug

[myredracer]

I also think the valve isn't opening. Need to access the valve to inspect it (and cable) which unfortunately isn't going to be fun. Ignore the tank readings as they are notorious for being incorrect due to sludge buildup on the sensors.

Another idea might be to add a cleanout in the 1-1/2" ABS pipe coming out of the grey tank if you have clear access to the pipe from below the underbelly. Could use "Fernco" fittings to insert a wye into the pipe if needed. Then use a snake to clear the blockage. But this isn't going to help much if the problem is the valve not opening.

Are you away on a road trip or near home? You could try finding an independent RV repair shop and plead your case and see if they can help you out for no charge.

When you do have it back to normal again, I'd suggest using a cleaning product to thoroughly clean all 3 tanks. Liquid Drano works great and won't hurt plastic or metal. There are others plus the "geo method". Need to drive around though to get it to slosh around.

[CarArt]

Thank you all for the time and the advice.

So I learned many think it's the valve despite the valve handle feeling just as it has for years. ? I know when my black tank valve broke, the knife blade from the cable rod, pulling on the cable went free, easily pulling in and out as nothing connected at the valve end. There wasn't.

I too thought 4000psi was liking to cause damage so no, wasn't so much a consider but reaffirmed the "theory" of backwashing the plug loose and hoping it would break up enough to flow out with on the 40-70maybe psi of my garden hose.

As I said, I'm in a park, disabled so other than taking my attached enclosed porch down, moving freezer, hiring a truck to come and tow me to an RV repair... it's last on the list. If I let 40 gals of gray water just flood out onto the ground. I'd be leaving permanently. Not happening.

I've tried a snake and as noted I don't "think" it ever got around the bends to the valve. Scratch the snake.

Ice has long been a solution for at least "cleaning" the tank some but again... you have to put in the ice and move around to agitate it. Pouring in ice standing still... nada. Cold greasy water.

I realized not much can be done from inside.

So, I'm going to crawl under after putting on my back brace, cut out the area where I believe the valve is located and see if the appears to be retracting/closing the knife blade or not. If it seems to be, I'll try forced water with the garden hose carefully to try and dislodge the plug, have someone watching under sink. Pushing against the water in the tank thats is full limits my optimism. But, If it moves and I get some outflow to lessen the amount of waste in the tank, I'll repeat till I get the surge or keep getting what I can out, maybe try some tank probiotics.

All else fails... s... I'll get some containers at home depot(40 gal), loosen the valve and let it drain, see whats up there, replace the valve.

One last question: from inside, I can get at the vent to the tank. I could get a pump to empty and insert the suction hose down thru the vent to the tank. I've tried to find a schematic of the plumbing system from Laredo but they said none available, acted like "why would we have such a thing" ??

Would one of you pros know if the vent tube goes directly into the top of the tank without bends?

[wnjj]

ppine wrote:
try adding a bag of ice and let it slosh around awhile.

Not sure how much sloshing there will be in a parked RV.

[ppine]

try adding a bag of ice and let it slosh around awhile.

[dougrainer]

CarArt wrote:
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

4000 PSI???????????? IF anybody has this done, have a Video Camera ready. The explosion would be worth seeing. In 40 years as a Tech, I thought I had seen or heard all the Hair Brain ideas.
1. There is something that was in the tank from build(hole cut out plug) that has finally migrated and blocked the exit fitting at the tank side of valve, BUT, that usually does NOT block off all water. It would still seep slightly.
2. The knife valve has broken loose from the rod or cable and stays shut. MOST PROBABLE CAUSE
3. There is NOTHING you can do from the inside at any of the sinks or shower. The plumbing will not react well to forcing from the inside and you will cause MORE problems than you have now
4. Running a snake back up thru from the outside on a 1.5 inch valve and possibly a 1.5 inch ABS pipe is almost impossible because of the various elbows involved
5. The BEST way is to just remove the valve and let the tank then drain. I know, on the ground.
6. IF there is some type blockage on the backside of the valve, the only sure fix is to remove the valve anyway. Forcing the debris backward will just cause the problem to come back later.
7. Since the RV is 10 years old, I would say there is NO construction debris causing your problem. Doug

[eHoefler]

Is the valve cable operated?? Very likely the valve is not opening.

[Joe417]

I've done what you suggest, but on the black tank. They sell a back flush valve that twists on like the drain hose. I think it was called a flush master. With the hose connected, you close the valve and turn the water on. I used it twice and it worked for me.

I had the wife watch and tell me when it started to come up inside so I could shut the water off quickly.

The issue ended up being a large #3 phillips screw driver in a bend of the pipe catching anything solid. No problem since removing it.

A couple of months ago, one of our forum members had an issue after using his camper about 5 years. He bought it new. Opposite of your issue but could be relevant. He drained his tank and then couldn't close the valve. He found a plastic drink bottle stuck in the Y of the drains. Your kitchen drain may be smaller pipe that a bottle could completely seal. I know a bottle wouldn't fit through the sink drain but since we're speculating, the hole was open before it was installed.

They also sometimes leave the plastic cut outs in the tank, what are the odds of having an issue with it.

Try the water back pressure. If the tank is empty and the valve is work it will prove that too.

[RV_daytrader]

Son of Norway wrote:
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.

I agree. your gray tank may actually be empty. All the water leaked out.