Grey tank leaking and repair - detailed

[jhulstedt]

We have been living in our 2007 Grand Canyon over 2 years now and this is the first time we have had this problem. A very bad putrid odor was coming from the cold air return for the forced air furnace. Finally I went out side underneath the beast looking for the source of the smell. I thought some animal died in there and I had to find it somewhere. I took off the front cover on the bottom where the #2 tank is housed (directly under the basement). Checked all possible locations and no signs of any leaks or critters.
Still worst putrid odor very pungent all over. Next unwillingly I decided I had to take off the corrogated black plastic belly at least as far back as the axles. I saw a slight drip and sagging about 4 feet back from the other cover. What I found is a puddle of putrid water on top of the #1 grey tank. This happens to be directly underneath the are inside where we where smelling this. Due to the openess of the construction air can pass quite freely from underneath up into the storage area/plumbing closet and directly into you home. A couple of weeks ago I forgot to open the #1 and #2 grey tank valves after flushing the Black tank. Discovered it and opened them immediately. I suspect we must have overflowed the tank and it spilled somehow out unto the top of the #1 grey tank.

What is supposed to happen when a user overflows any of the tanks? Where does the excess or overflow supposed to go? Is there something in the design to spill it onto the ground. For instance If someone should overflow the black tank while rinsing where does the water go. I do not see anything as I looked for the source of the problem. Is the design such that it overflows inside the belly of your coach? Is there some sort fail safe drain or shutoff in case of an accident such as forgetting that you left it on.?

But in my case is there something wrong with the tank. I have seen posts that say that it should back up into the sink but when I purposely overflow that tank (after using a gallon of bleach and filling) it pours out over the top on the tank and on to the ground as it is now with the cover off. With the cover on it would pour directly onto the limited fiberglass insulation I found and on to the black corrogated black plastic cover. Why would the water so freely just flow over the top of the tank and onto the ground. Is there some sort of vent or other opening? I suspect others have had this problem after reviewing the posts on this website.

Also how are the input pipes into the tank sealed on top. I can see them barely using mirrors and a flashlight. Are they fitted into rubber type grommets that allow removal or are the pvc glued into the tank.

I appreciate any help I can get as to the construction and design so I can repair this.

Thanks!

 

[Uncle Rog]

I do believe you have a leak, obviously, from where I have no idea, the tank vent possibly? As far as I know when the gray tank is full it will back up into the sink(s) or shower. The black tank will fill up to the obvious place. Your question about the black tank using the sani-flush feature, and over filling, is not pretty. I have read and heard of several people not opening the valve during use. When the ball in the toilet is closed there is no escape for the contents and with a high pressure rinse the tank expands to its max point and explodes......best not to leave the unit on if unattended.

 

[jpmorgan37]

jhulstedt;

I would hope that the factory weighs in on this quickly, but if I overfill my grey tanks on my Grand Canyon, # 1 backs up in the shower and I don't know about #2 because I've never overfilled it. I know my black tank will back all the way up into the comode, because I have filled it that full intentionally several times before I dumped it. At any rate, I have not had a leak (so far) thankfully.

John

 

[jimtoo]

Just as a guess I am thinking you have a cracked or broken vent connection on the top of the tank. There would be no other reason for it to get on the top of tank that I could think of. Drain tank, start filling and watch underneath with mirror to see if you can see where it is leaking. I am pretty sure the fittings are pvc glued.

 

[Terry H]

I had a similar problem on the gray water tank for the kitchen. It turned out to be a cracked threaded fitting at the top of the tank. The drain is attached to the tank by a thread to slip (glued joint) adapter. Have some one run water into the tank and see if you see where the water is leaking from.

 

[jhulstedt]

[FONT=Verdana, sans-serif]The problem was a cracked 1-1/2" adapter fitting that is threaded into the tank. All the pipe up to that point is indeed 1-1/2" PVC pipe with glued fittings. The reason it cracked is that this particular tank has a huge concave top and the fitting is to weak to support the stress. My other tanks, which are the same model from Americart, have convex tops. [/FONT]
[FONT=Verdana, sans-serif]This broken fitting problem would be very costly and difficult to fix had it not been that the location of the fitting was directly underneath the box that is first step into the upper level. Otherwise there is just no way to work on it. I thought about dropping the tank. But I found out to drop the tank would mean cutting the vent pipe then you have to disconnect the drain connection. After that then the support angle iron bar would need to be removed. Then the tank would need to be slid out from the other support that is welded to the frame. All of this would be very time consuming and difficult to do. And if you did do that how do you connect it back up?[/FONT]

[FONT=Verdana, sans-serif]What I did first is gently removed the 3 trim pcs on the first step. There are just a few pin nails and a minimum amount of silicone holding it down. By the way that first step creaked all the time anyway. When I got done and put it back I fixed that also. Next I used a flat bar and pried off the 1/2" plywood top. There where a lot staples in it I so just worked it up slowly all the way around. Once I got access in there I could see the fitting because the water supply cutout is right next to it. This is really just a coincidence that it is there. [/FONT]


[FONT=Verdana, sans-serif]After that I cut out more of the flooring around the original hole to get better access to the area and so that I could work on it. It ended up being about 6 to 8" square. I then cut the top pipe really close to the elbow that goes down to the tank. Then I made a couple of cuts about 1/4" apart in the fitting that was screwed in the tank just enough so that I could gently break out that pc and then pried out the rest of the threaded ring again being careful not to damage the threads. I was careful to not go to deep with those cuts so as not to damage the threads in the tank. If I had the right tool I probably could have just unscrewed the ring or made something possibly to wedge in the ring and backed it out. But I did not know it was threaded at the time. I could see that the pc would move slightly when I pried it. [/FONT]


[FONT=Verdana, sans-serif]From the top of the tank to the bottom of the floor is only about 5". So getting some 1-1/2" PVC pipe in there and an elbow and adapter fitting is really close. But I went to Home Depot and got Schedule 40 pipefittings these fittings are designed for pressure applications and are stronger than the drain type fittings. Also the adapter is made such that it did not have a groove right where the fitting cracked at the end of the threads. All these fittings are thicker and made without a lot of shoulders and corners and tight radii which makes them less susceptible to cracking. I had to cut off about 1/4" of the slip fit end of the adapter and the elbow to make room to get all this stuff in that space. [/FONT]


[FONT=Verdana, sans-serif]I screwed in the adapter with a bunch of Teflon paste used for CPVC applications and tightened it and then inserted the rubber slip fit adapter with its hose clamps on to the pipe I cut earlier coming from the sink and pushed it back on the pipe as far as I could so it was out of the way. The fitting actually went almost out of sight under the floor. I then glued a small pc of coupling pipe into the threaded adapter and then glued the elbow on top of that. By the way it is the tightest radius elbow I could find so as to take up the least space. There was no gap between the elbow and the threaded adapter. This elbow had on one side a female adaptation, which went down, and a male portion on the other side that came right flush and in line to the pipe that I cut earlier. I then slid the rubber adapter over these and tightened the hose clamps. [/FONT]


[FONT=Verdana, sans-serif]I then started to close it back up I sealed up the floor with a pc of plywood to cover the 6 to 8" hole and taped up the black moisture barrier and insulated the area as long as I was there. I screwed on the top on the step and fixed that annoying creaking that was there. I glued the trim pcs back on with some clear silicone and put some more pin nails in them with my pin nail gun then stapled the carpet pcs back on that got pulled away.[/FONT]


[FONT=Verdana, sans-serif]All in all it was not that hard to do. The worst part was not knowing how it is put together and getting to it. That is why I thought this might be useful for someone else. I am pretty confident this is a good fix and will not have the problem again.[/FONT]

 

[Ray LeTourneau]

Jim, Thanks for the update and the step by step repair you did. Very helpful to others.

 

[Booker]

I think this may turn into an epidemic! 2007 Landmark Grand Canyon - same problem but this on is on the #2 gray tank and #1 gray tank is suspect as well.

First I had water dripping from the belly of the beast under the cellar. The cover of the undercarriage began to sag as well. I took it off and everything was soak, mildew, chip board was dissolving, etc. etc. What a mess!

I purchased the Landmark this past April 2009. So this problem has been going on for sometime now.

Thanks for your insight into the problem, but I'll bet the farm, this will happen to all three tanks. You know that the same problem fitting was used on them all!