Tank drain doesn’t go all the way in.

[GIBBYVETTE]

Last week emptied black tank. The tank drain valve didn’t seem to go all the way in but I pressed it hard and thought it was normal. After a tailgate I went to empty the black tank. As I took the plug off waste fluid came gushing out. I quickly got my drain hose on so was mildly filthy. As you can see in photo I can’t get waste drain valve all the way in. Feels like some resistance. Winnebago 2022 Adventurer class A. Thoughts?

 

[Tulecreeper]

Obvious reply - you have something blocking your blade valve and keeping it from closing completely. Best guess is a big wad of TP, unless someone dropped something else down the toilet like a paper/plastic cup, tampon, face mask, etc.

 

[GIBBYVETTE]

How do I get to it?

 

[Tulecreeper]

I can't tell by the angle and closeness of that picture how much room you have and what you actually have to work with. I had to replace a black tank blade valve one time, but it was right out in the open and not behind any kind of exterior cover like you have. If you can access the entire valve it's actually a pretty easy job to pull it and replace it. You know, dealing with some of the contents notwithstanding.

 

[TonyL]

You have cable operated valves from the look of it. In our experience, they're always useless at shutting properly.
Fit an extra valve to the outlet and then you will no when it's shut.

 

[Rene T]

You have cable operated valves from the look of it. In our experience, they're always useless at shutting properly.
Fit an extra valve to the outlet and then you will no when it's shut.

Correct. I changed all 3 of mine to direct operator and I did away with the cables. They are junk.

 

[Rene T]

As I took the plug off waste fluid came gushing out. I quickly got my drain hose on so was mildly filthy.

That’s an easy fix. Just get a Camco twist/spin on valve and install it at the end of your sewer pipe. This valves serves as a backup valve in case one of your drain valves leaks a little. Keep a cap on the outlet of that new valve for cleanliness. Then after removing the cap, connect your sewer hose then open that valve to release any liquids that may be in the sewer pipe.

 

[Kirk]

How do I get to it?

The first thing is to find out exactly where the valve is located. You can download a drawing of the plumbing from this website, using the exact model number. The drawing should look similar to this one.

In this case there are 2 valves, each labeled as V-7. It is difficult to tell from the picture you posted, but the valves might be directly behind the handle and if so that would be the easiest to replace but if not there may be a cable operator. You should be able to see for sure what you have by using a mirror to see behind the white plastic. If it is located there you should be able to replace it fairly easily, once you remove that white plastic facing.

 

[My To Good Hands]

Last week emptied black tank. The tank drain valve didn’t seem to go all the way in but I pressed it hard and thought it was normal. After a tailgate I went to empty the black tank. As I took the plug off waste fluid came gushing out. I quickly got my drain hose on so was mildly filthy. As you can see in photo I can’t get waste drain valve all the way in. Feels like some resistance. Winnebago 2022 Adventurer class A. Thoughts?

I found that lube helps them move smooth, while they are not lube able I came up with a plan.

Here is my solution.

 

[jubileee]

If you have blockage at valve, you can back flush through a cap that has a hose connection

 

[John From Detroit]

If you have blockage at valve, you can back flush through a cap that has a hose connection

I was about to make that suggestion. Also fill the tank as full as you can with just water and dump (Into a proper sewer inlet) for the WOOSH factor to try and blast out what ever is obstructing.

 

[Gizmo]

I was about to make that suggestion. Also fill the tank as full as you can with just water and dump (Into a proper sewer inlet) for the WOOSH factor to try and blast out what ever is obstructing.

You guys beat me to it. Both ideas have merit. I had the same issue on my last rig (a 5th wheel). I first filled the tank and pulled the valve, as this did not work I did it a second time and still no difference. I then went to Walmart and picked up a backflow unit that connected between the rv's sewer pipe and a sewer hose with a connection for a water hose - that worked.