Grey tank leaking

[Thunderman]

2955rl I leave the galley tank open , when leaving camp area I drain black tank first then close that valve and drain the grey tank. I thought leaving the galley tank open would let that water go to the other grey tank. Have never had a problem. Today I read that leaving the galley valve open will send that water to the black tank. Is this correct?
The grey tank (shower) has started to leak after taking after use of about 4 times. Leaking thru coroplast. I thought that would be due to bad seals but after reading a bit more now i am not sure.
Thanks for your thoughts.

[Mikendebbie]

Not sure about your particular model - but I believe the gray and black tanks will be piped to a common header pipe where your sewer hose is hooked up and out to the campground sewer. The gray and black tanks have dedicated valves to open and close each tank. I don’t think the tanks are plumbed to allow gray to flow to black or vice versa. In camp, I leave my gray valves open, and only open black valves when they get sort of full…I drain and rinse the every other day or so. I do not trust the control panel indicators for “full”. They are unreliable.

Bottom line - I don’t think your tanks are connected in any way to allow what you suspect is happening - to happen. As to the tank leak - it sounds like you may have a cracked tank. There are many threads on that subject here and you can find advice for a tank repair or replacement.

[Carl n Susan]

I don't know what year 2955RL you have but I am guessing it is pre-2010 and the dropped frame design. All three of your tanks are on the same level (unlike the dropped frame models). Each tank has its own gate valve to isolate it from the others. But they do share a common drain line.

If you should happen to open two valves at the same time you will get a little cross-pollination during the dumping. If one was the black tank, then there might be a touch of sewer in the other grey tank until both finish draining.

On my 2955RL I had added a gate valve at the sewer outlet. Not only did it stop the little surprises when you removed the cap, it allowed us to share tank capacity when boondocking. By keeping the drain outtet closed and opening the valves on the grey and galley tanks (*NOT THE BLACK Tank*) you could equalize the two tanks and maximize the water being stored. Obviously you don't want to use the black tank, although it is possible, in this process.

As long as you keep each individual tank valve closed, no other draining tank can pollute it.

[RMcNeal]

Carl beat me to it. Great explanation. I would add that when I drain the black tank, I leave the black tank valve open then close the valve at the sewer outlet and open the gray tank valve. I wait a few minutes to allow the draining gray water to back fill into the black tank to help flush it out, then open the sewer outlet valve and drain both tanks until nothing flows. I then close the gray and flush the black with black tank flush in the convenience center. If you have a fairly full gray tank, the extra water helps get TP and other "stuff" out of the black tank without using as much water in black flush.
I never use the galley gray tank in this process, just in case the black tank contents get into that tank. I don't want that smell in the kitchen.

[Thunderman]

thanks all for your comments. I did not think the galley water would be going into the black tank. Happened to read another source and was indicated the galley DID go to the black.
Seems my grey tank, shower may have a crack in it.

Thanks again!

[DutchmenSport]

As stated above, your tanks are all on independent valves of each other, but they may flow into a single outlet.

About that back flushing, here's how it works.

The black tank and the grey tanks are on separate valves, but both pipes join in a Y at a common outlet where you attach your sewer hose (stinky slinky).

Normally, you attach your stinky-slinky and pull the black tank water first until it quits. Then you pull the grey valve and let it flush out the stinky slinky until it quits. And now you are done.

In order to back flush, you need to attach to that outlet a Flush King type of attachment: Click here so you will see what this is.

There are several different knock-off brands that are just like this and cheaper too. I have one and it's worked well for over 20 years. Any RV dealership parts store will have them, even Wall Mart does in the camping section.

You attach the "Flush King" to your outlet and your stinky slinky to the Flush King.

Now, the steps are simple.

Open the Flush King and open the black tank valve and drain completely the black tank. You can tell when it's finished because of the clear section in the pipe. And yes, you want the black tank as empty as possible to go to step 2.

Step 2, Black tank is now empty. Close the Flush King and open the Grey water valve. This will let the grey water back-flush into the black tank. Count o 10 and then close the grey tank valve.

Step 3, Open the Flush King valve again and dump the black tank again. This is the first flush. Sit back and be amazed how much MORE stuff you see coming out of the black tank through the clear section of hose.

Step 4. When you are done with the backflushing, close the black tank valve and now open the grey tank valve to do a final rinse of sewer hose.

You can repeat this process over (step 1 through 3) several times, depending on how much water is in your grey water tank. When our grey water tank is full, I can easily back flush 3 times and still have some water left to flush out the hose.

This is how you back flush.

But no where is there a set up for the black and grey tank to mix on their own. They are separate systems, they just share one common final outlet.

[twindman]

I see no need for a Flush King or anything like this. The Black tank has a backflush system that is probably better than the flush king. The water goes directly into the black tank. I alway drain, close valve, run the backflush for 5 minutes and dump again. If it wasn't pretty clean water, I repeat this. I figure I can't overflow the tank because that would be over 8 gallons per minute, or 1 gallon in 7.5 seconds. No hose is that fast.

[RMcNeal]

I purchased the flush king with my last TT which didn't have the black tank flush. However, even with the Montana, I don't have a way to flush the gray tanks. How do you go about cleaning those? Despite my best efforts, food particles and junk end up in the Galley Gray tank. I'm constantly amazed at how much.

[twindman]

I suppose food, etc could build up. But both the gray tanks really gush out the sewer line when I dump. So I would think most particles would get swept out with the water.

[mhs4771]

Gray tanks are simple, on travel days put 10 to 15 gals water into the tanks, add some laundry soap and drive. At your destination hook-up the sewer line and drain.

[RMcNeal]

Originally Posted by mhs4771

Gray tanks are simple, on travel days put 10 to 15 gals water into the tanks, add some laundry soap and drive. At your destination hook-up the sewer line and drain.

I recently tried using 1 cup Borax and 1 cup Dishwasher Powder and put in 15 gallons. Drove for about 200 miles and drained. I really didn't notice a difference in the galley gray tank and the sensor didn't start working again either.
What kind of laundry soap, powder or liquid, or does it matter? I was told to use the dishwasher stuff, cheapest at Wal Mart, so it didn't suds up so much.
I've been thinking of trying the Unique Digest It. They also have a tank sensor cleaner out now. Any experience with them?

[ccl]

Originally Posted by Thunderman

2955rl I leave the galley tank open , when leaving camp area I drain black tank first then close that valve and drain the grey tank. I thought leaving the galley tank open would let that water go to the other grey tank. Have never had a problem. Today I read that leaving the galley valve open will send that water to the black tank. Is this correct?
The grey tank (shower) has started to leak after taking after use of about 4 times. Leaking thru coroplast. I thought that would be due to bad seals but after reading a bit more now i am not sure.
Thanks for your thoughts.

What year is your 2955rl? I have a 2005 2955rl, 2 years ago the grey tank was leaking this year the galley tank was leaking. Both leaked where the the drain pipe goes into the tank.
If you are going to fix it yourself might as well do both.

[EagleRunner]

If I understand you correctly, it is not the valve that is leaking but rather the tank itself? If that be the case then due to the design of the 2955RL, the grey or black tank may develop stress cracks near the output of the tank, in the collar region. If let go these eventually start leaking. The grey tank is most common for this luckily. I had mine crack and develop a leak some time ago and did the repair myself. It requires dropping the cover, pealing back the insulation and preparing the leak area for patching. I found a product on the market called Plasti-Mend that repairs the tank and makes that area stronger than the original tank material. Long story, but it actually molecularly molds into the tank material forming a solid patch. Strongly recommend drilling small holes in each end of the crack to prevent further cracking. Then sand the entire area of the crack one inch beyond the crack. Follow instructions provided with the product to the tee, including safety precautions. Vapors from this stuff is highly toxic.

Mine has held now for five years and hopefully as long as I continue to use my 2955RL. Good luck with your repair.

Tom

[jpwhite]

Originally Posted by Carl n Susan

I don't know what year 2955RL you have but I am guessing it is pre-2010 and the dropped frame design. All three of your tanks are on the same level (unlike the dropped frame models). it.

Carl n Susan,
Can you clarify your comment for me? I have a 2019 3120RL. There are two gray tanks and one black. There are the shower / bath room, galley gray tanks, and the black. Do you know if they are all on the same level /and if not, which may be on the same level? It will make a big difference in attempting to share gray capacity or back flush the black.

Thanks,
Jim

[The Sandcarver]

Several years ago I posted how I fixed a leak in my tanks drain lines. They are black ABS so I used the black glue from big box store and a roll of the fiber glass sheet rock tape.

If possible find the crack and drill a very small hole at each end of the crack to stop the crack from continuing.

Rough sand the pipes with like 80 grit paper and clean with lacquer thinner. Cut pieces of the glass tape. Apply a layer of ABS glue to the area and then 'wrap' the entire area to be worked on. Work the tape into the glue. Smooth out and let dry. Cut more pieces and repeat. When satisfied that you have covered a sufficienty large area your done. I went big.

I did this repair about 5 years ago and have had zero problem since.

John

[Carl n Susan]

Originally Posted by jpwhite

Carl n Susan,
Can you clarify your comment for me? I have a 2019 3120RL. There are two gray tanks and one black. There are the shower / bath room, galley gray tanks, and the black. Do you know if they are all on the same level /and if not, which may be on the same level? It will make a big difference in attempting to share gray capacity or back flush the black.

Thanks,
Jim

The black tank and the shower tank are in the dropped portion of the frame. The galley tank is above the axles in the upper portion of the frame. I would not try to equalize the two grey water tanks. The height difference means the shower tank will fill first and then the galley tank. There have been many, many problems when a tank is filled to capacity (lids popping off). The galley tank being higher will increase the pressure in the lower shower tank as it fills making the lid popping situation worse.

You may have the roto-moulded tanks that are all one piece unlike the older tanks. They may be stronger but they haven't been out long enough to say they can handle the pressure.