Grey water leak on top of grey tank?

wilsonxjr

Member
Hello fellow RV'ers ...
2021 Cyclone 4007. Need a crash-course on waste tanks.
Noticed some bulging in the front underbelly of our rig. The 'sloshing' sound when pushing up on the underbelly confirmed it was water. Dropped the front underbelly to drain the water and took off the basement access walls. Big puddle of water on top of my grey #1 tank with evidence that it had recently been a bigger puddle and overflowed down the sides of the tank on to the underbelly. Water had a 'soapy' smell so assuming it was drain water, not fresh or black ... also no evidence that any of the fresh water lines are leaking.

Some context ... it's normally just the two of us and we try to dump regularly since our tank level indicators have never been reliable. A few weekends ago, we had some family stay with us and our grey #1 tank filled-up to the point that the shower drain backed-up.

So my question ... when a grey tank gets full, is there some kind of overflow valve on the top of the tank or do I have some kind of defect in the tank? I can only see about 1/4 of the top of grey #1 as the rest is under the basement floor. Can't think of any other way grey water would get on top of the grey tank. Unless it's fresh water spraying from an occasional leak?

Anyone have any ideas?
 

thewanderingeight

Well-known member
Best thing to do would be to recreate the full tank, and then watch to see if you can identify where the water is coming from. Best case scenario is that it’s just a loose fitting that is leaking when it got put under pressure. A cheap scope cam may help.

Good luck!


Sent from my iPhone using Tapatalk
 

david-steph2018

Well-known member
It could be the vent pipe to the roof is loose or has come out of the tank. Another possibility is a loose drain, look at the shower drain at the bottom of the shower pan. Our shower drain was loose and caused a small leak there.
 

BigFry

Member
The gray tank (at least on our Bighorn) has two holes on the top. One hole is for the drain into and one for the vent to the roof. There is a rubber grommet that is placed in the hole to hold the pipes. To my knowledge they are not glued but just pushed into the grommet. You would be surprised how much the tank swells when full and the pressure put on the connections, especially the bottom drain. I would not have believed it if I had not seen first hand. You may have a loose top connection of the vent pipe if it only leaks when completely full. Attached is photo of the top side of a tank.
 

Attachments

  • Bighorn Gray Tank IMG_3667.jpeg
    Bighorn Gray Tank IMG_3667.jpeg
    1.3 MB · Views: 68

wilsonxjr

Member
Thanks for the responses everyone! I have fairly easy access to the drain and vent ports in to the tank so will do a test and fill-up the tank and watch to see where the leak is coming from.
 

bwdt

Well-known member
My black tank was leaking from where the rubber gasket is supposed to be. They cut the tank holes to big for the gasket to be tight so it leaks. They probably did the same on the grey tank. Mine is now leaking if I ever over flow the tank. My other issue is that the tank is sagging extensively below the frame rails. bowed about six inches down and two below the rails. I'm going to add a support under the tank and weld a flange mount where holes in the tank are, then install a flexible hose with clamps to the drain and vent pipe. really bad design..on Heartlands part.
 

jkmetic

Member
Thanks for the responses everyone! I have fairly easy access to the drain and vent ports in to the tank so will do a test and fill-up the tank and watch to see where the leak is coming from.
I would love to hear what you find out as I just discovered mine is doing it as well. Ugh…..
 

taskswap

Well-known member
Check your sink and other plumbing TO the tank as well. In our Milestone, Heartland hadn't tightened down the fitting for the P-trap on our kitchen sink and we were getting similar puddles of water on top of one grey tank as the sink was used - it would flow down the side of the pipe onto the tank.
 

"Hi-Viz" Bill

Well-known member
Hello !! .. We had the exact same problem on our '16 Landmark 😰 .. We had to have our grey tank replaced !! .. Upon removal, we discovered the tank was of 2-piece construction .. an area of the joint or fusion of the 2 pieces had become separated, when the tank was approaching a full status, the joint would separate and leak as fast as water was entering .. the gaskets, and vent pipes were WERE NOT leaking !! As a result, I am very careful, as too not fill the tank too full, to reduce the chance of creating an internal pressure and stressing the joints once again !!
 

bwdt

Well-known member
I got an update on more info regarding tanks. I talked with the manufacturer of the tanks, in my camper they were made by Atlas. They told me that they tell the companies who use them that they need to be supported underneath. If not they will stretch and deform and eventually crack. The RV manufacturers tell them to make them to their spec. and they will use them how they like. If they don't like it they will just use a different manufacturer. Here are some pics of mine. They have stretched below the frame rails. about six to eight inches. I'm pulling the grey tank to inspect and then adding supports under all tanks. Keep in mind that my tanks have never traveled with much water in them, usually empty except for twenty gallons in the fresh water tank to use the toilet if necessary. When I did talk to Heartland, they tried to say that I must be overfilling the tanks. LOL. how do you over fill a 45 gallon waste tank? She couldn't tell me. LOL. Here is a pic of my stretched out tanks. You can see that the grey tank, bottom one is below the frame rail and the black tank is hitting the top edge of the grey tank. I picked up some 1.5 X1.5 11 gauge steel square tubes and will put some protected plywood on top of them. This will be done for all tanks. I have two grey tanks, 1 black tank and a fresh water tank.
 

Attachments

  • 20240708_124707.jpg
    20240708_124707.jpg
    1.1 MB · Views: 26

taskswap

Well-known member
Wow, looks like you were a few bumpy roads away from even bigger pain. Better have a look at both ends of those water lines when you're in there. Looks like they've had some strain on them from the bulging.
 

bwdt

Well-known member
Update. I was under the camper to start repairs. and found that the black tank had completely fallen through the mounts. Its sitting on top of the grey tank. It looks like the supports were put in the wrong location. (to far apart.) I now have to rebuild the plumbing on the tanks, re mount the supports in the right place, and I'm adding an under support on all tanks including under the basement storage location. I also found that the drains into the gray tank are leaking, and I will check this out. And it has never been on bumpy roads. Total road miles for this camper is about 7000 miles since new. I'll add pics when done.
 
Top