Advice Needed

[bwalton]

Every time I empty the black tank, I thoroughly flush it until the water coming out looks clean. I then shut off the tank flush and let leave the valve open until it stops running. Then I close the black tank valve. I then empty both gray tanks until they are as empty as possible and close the valves.

When I'm done and I unhook the sewer hose, there is nothing trickling out. I then cap the system.

The problem is the next time I open the cap to attach my sewer hose, a lot of green water (I am assuming from the black tank because of the color of chemical I use) comes streaming out of the pipe. I cannot figure out what I am doing wrong. Like I said, when flushing the black tank, I flush it until the water runs clear. How is this extra liquid getting into the pipe? Could the tank be plumbed wrong so that much is hanging up in the pipes until I move the trailer?

Any ideas for a solution?

Thanks in advance for any and all help.

[us71na]

What do you mean by " a lot of water" is it a quart, gallon or several gallons? Chances are you have a lump of solids & paper on the bottom of the tank that is saturated with water. Just opening the drain doesn't get rid of this, so when you close the drain the water slow seeps out into the drain.

[abarkl]

Perhaps you have a leaky valve. They can typically be removed to clean if needed, may have something such as toilet paper stuck in it and not allowing it to fully close, or have damaged or missing seals.
Using something such as petroleum jelly the seals can be reconditioned. And the valve pull shaft should be lubricated with something like white grease.
They are fairly inexpensive as well.

[bwalton]

Between 1/2 to 1 gallon.

I have been camping since the middle of August at a member's only campground. I have to move sites every two weeks. There isn't time for this much water to leak slowly from the time I unhook the sewer until I hook it up again. Usually less than 20 minutes. I have been emptying the black tank weekly. I wait until it is about 2/3rds full then I fill it with water before I empty to ensure that there is plenty of water to wash the solids out. Plus, we use a lot of water after each use.

When I'm flushing I close the valve for a few minutes (I never walk away and I do it several times since we are at a full hook-up site) and it doesn't leak out then. I would think as the pressure builds behind the valve as the tank fills it would leak if the valve was partially blocked open.

When setting up I tend to error on the side of the door being higher than the road side. Not much (never more than 1/2") but if I can't be perfectly level I want the door side higher. My thought on that is to ensure that the tanks empty properly. Maybe that is the wrong idea?

[bwalton]

I thought about the leaky valve also. If that is the case I'm going to have the dealer replace it. The trailer is only a couple of months old.

[Proud Grandpa]

I had this same problem, but it was gray water. Looking under the trailer, I noted the piping running from the gray water tank to the discharge valve, about 6' of pipe, was higher in the center than either end. This caused to tank to not drain completely, then when the trair was moved, the water would drain from the tank and become trapped at the discharge valve. While the trailer was at the dealer for other repairs, I brought to their attention. They repositioned the piping and no more problems.