Black tank not draining. 2017 Vista 29VE

[monytaker]

HI all,
Have a 2017 Winnebago Vista 29ve. Stopped at dump station to empty tanks yesterday. Pulled the black tank release valve and just got a trickle. Fluid not coming out. Tried the grey, no problem with draining there.
We only use for number one and put no paper down. Can't figure this out. Any suggestions? Am hoping maybe ride home juggling things around might help but can't figure out why just fluid in there wouldn't drain.
Thanks for any help.

 

[Morich]

Some depends on your experience with RV!
Have you experience with how to treat the black waste to avoid clogs or has the cable to pull the valve open failed?
If one is not used to treating the black, we can create too much waste that is not broken down enough to drain . Do you have a bunch of liquid that is stopped by a closed valve or do you simply not have enough liquid waste to run out and it needs to have more water and chemicals to make it run?
Adding chemicals and water, then waiting is the solution for getting a clog broken down but the second will often require getting to the cable to check it is attached all along the route and at the valve.
Valves can get stuck when they dry out and there are times when the clamps along the pull wire come loose. If the clamps are loose, the wire and cover can just move around, rather than moving the valve.
This is looking up[ at the RV from bottom!

 

[Pointyears]

HI all,
Have a 2017 Winnebago Vista 29ve. Stopped at dump station to empty tanks yesterday. Pulled the black tank release valve and just got a trickle. Fluid not coming out. Tried the grey, no problem with draining there.
We only use for number one and put no paper down. Can't figure this out. Any suggestions? Am hoping maybe ride home juggling things around might help but can't figure out why just fluid in there wouldn't drain.
Thanks for any help.

Mechanism probably needs lubricating. When you pull the lever, the slide actually isn't retracting.

 

[monytaker]

Mechanism probably needs lubricating. When you pull the lever, the slide actually isn't retracting.

How would I go about lubricating the mechanism

 

[monytaker]

Some depends on your experience with RV!
Have you experience with how to treat the black waste to avoid clogs or has the cable to pull the valve open failed?
If one is not used to treating the black, we can create too much waste that is not broken down enough to drain . Do you have a bunch of liquid that is stopped by a closed valve or do you simply not have enough liquid waste to run out and it needs to have more water and chemicals to make it run?
Adding chemicals and water, then waiting is the solution for getting a clog broken down but the second will often require getting to the cable to check it is attached all along the route and at the valve.
Valves can get stuck when they dry out and there are times when the clamps along the pull wire come loose. If the clamps are loose, the wire and cover can just move around, rather than moving the valve.
This is looking up[ at the RV from bottom!
View attachment 1338399

 

[monytaker]

Thank you for your reply. I find it hard to believe I would have a clog due to how we use the toilet. That said we were camping for 3 days and black tank monitor was reading 1/2 to 2/3 full. Will have to investigate the cable situation further.
Thanks for the diagram.

 

[Morich]

It may be hard to judge the feel of the handle as we open/close it but it may help to try to note if it feels like the wire is still attached to something at the hidden far end or if it feels totally loose. More like if the wire is stiff and may be trying to move the valve but can't or is it just not pushing/ pulling on anything like it is no longer attached to the valve.
Different things can happen and each requires different things to fix. But in your RV design, the wire run is quite long and that opens up a bit more different ways to fail.
Do you have an experience with the controls on lawn mowers or bikes? Things where there is a wire inside a coiled wire and that inner wire moves the things we want to control?
Same basic idea on the RV drain valves!
We try to fasten the outer layer to stay in one place, while we move the inner wire to control whatever is at the far end. And both controls can have the same problems.
The far end valve can get stuck full of grime and waste that becomes hard and it can almost seem to freeze the slide solidly to the rest, so we can't get it to move.
This can become more likely if we think of what comes out of the solid waste. If we drain that and don't run some water through to clear any remaining solids out of the space where the sliding part moves, that leftover waste can dry and become almost like brick! Nearly impossible to clear without getting to that groove and scraping it out.
There are times when I have cleared this but it takes luck! Worth the effort but sometimes luck helps!
If you feel the valve body is stuck/grimed up with waste that may have dried in that groove, it "may" help if you can invent a way to let water stand in the valve body for a day or so. Water may loosen up the block of gunk and it may then flow on out? Add the drain tube and put the end high while leaving water standing at the valve?
But the metal shaft on the valve may have rusted and stuck to the rest! That may really require getting in to scrape and lube the parts to get them to move. If I understand you to mean the only waste is urine going down, keep in mind that it is pretty corrosive stuff and that may be the problem if not diluted well!


Other options that you might find are the handle rusted or the wire inside the coiled wire may also be stuck or rusted. breaking the bond and freeing movement is likely to be difficult if not able to get hands on it to move it and soak it in lube.
Or the clamps that hold the outer coiled solid to make the inner wire move may come loose. That is like the lawn mower controls and the outer has to stay in one place to get the inner to move like we want.
Access to redo the clamps may be needed.

Most of this is ugly work while laying on our back under the RV!
Not the best way to spend a weekend!

 

[monytaker]

It may be hard to judge the feel of the handle as we open/close it but it may help to try to note if it feels like the wire is still attached to something at the hidden far end or if it feels totally loose. More like if the wire is stiff and may be trying to move the valve but can't or is it just not pushing/ pulling on anything like it is no longer attached to the valve.
Different things can happen and each requires different things to fix. But in your RV design, the wire run is quite long and that opens up a bit more different ways to fail.
Do you have an experience with the controls on lawn mowers or bikes? Things where there is a wire inside a coiled wire and that inner wire moves the things we want to control?
Same basic idea on the RV drain valves!
We try to fasten the outer layer to stay in one place, while we move the inner wire to control whatever is at the far end. And both controls can have the same problems.
The far end valve can get stuck full of grime and waste that becomes hard and it can almost seem to freeze the slide solidly to the rest, so we can't get it to move.
This can become more likely if we think of what comes out of the solid waste. If we drain that and don't run some water through to clear any remaining solids out of the space where the sliding part moves, that leftover waste can dry and become almost like brick! Nearly impossible to clear without getting to that groove and scraping it out.
There are times when I have cleared this but it takes luck! Worth the effort but sometimes luck helps!
If you feel the valve body is stuck/grimed up with waste that may have dried in that groove, it "may" help if you can invent a way to let water stand in the valve body for a day or so. Water may loosen up the block of gunk and it may then flow on out? Add the drain tube and put the end high while leaving water standing at the valve?
But the metal shaft on the valve may have rusted and stuck to the rest! That may really require getting in to scrape and lube the parts to get them to move. If I understand you to mean the only waste is urine going down, keep in mind that it is pretty corrosive stuff and that may be the problem if not diluted well!


Other options that you might find are the handle rusted or the wire inside the coiled wire may also be stuck or rusted. breaking the bond and freeing movement is likely to be difficult if not able to get hands on it to move it and soak it in lube.
Or the clamps that hold the outer coiled solid to make the inner wire move may come loose. That is like the lawn mower controls and the outer has to stay in one place to get the inner to move like we want.
Access to redo the clamps may be needed.

Most of this is ugly work while laying on our back under the RV!
Not the best way to spend a weekend!

Ty will move forward with some of those options and hope something works. Appreciate your assistance.

 

[monytaker]

Ty will move forward with some of those options and hope something works. Appreciate your assistance.

Just a followup. Guess the juggling around on the trip home helped. Went out to tackle the black tank. Pulled the lever and it started draining.
Thanks again for your responses. Will keep them in mind if it happens again.

 

[Morich]

Whether it is true or just stretching for some explanation, maybe consider this wild guess?
If the sliding portion of the valve was stuck due to something like minerals from water drying in the groove where that sliding panel sets, had collected and gotten hard, was it having water to soften those mineral enough to let the slide move?
Weird things can happen when we are dealing with mechanical stuff tucked way back where we can' t see it!

If it was something you could get to in any practical way, I might suggest a good soaking in something like WD-40! But I don't think that will work in your case!

Will wish you better luck on the next trip and will say there can be times when things do clear up and never come back!
Maybe you had one of those "gremlins" hung in the works and once he got loose, he will move to a different RV?

 

[RayIN]

The gate valve seals can dry out and make the sliding blade hard to move. Commercial valve lubricants contain coconut oil, so just buy a small container of liquid coconut oil at the grocery store and pour it into the black tank after you have emptied it and closed the valve, and let it sit for as long as possible. It's best to add enough to completely cover the valve.
I keep the valve cable lubricated with penetrating oil by adding a few drops onto the cable when the handle is pulled fully open. The oil will eventually work its way to the other end.

 

[Gkpasco]

It may have been mentioned but if the exhaust venting is plugged by whatever, that also will cause the tank not to empty as it should. Just my 2 cents.