Black water dumping problem

[martinto]

New Slingshot this spring and have camped 3 times. I dump the black water first then the grey water. The 2nd time, I had a sewer line at my site and was able to really flush both tanks. When I went to dump the black water this week, I got a small residual when I removed the cap to install the hose. This would suggest a small amount was getting by the closed valve. Anybody have experience with this or suggestion on what the problem may be?



As an aside...I also used a clear elbow with hose flushing this last time and got both tanks flushed to a clear water level.

[Hunter11]

I think everyone has had this problem at one time or another. Either something is hung under one of the valves or one is not closing all the way. If your valves are remote like ours it can be a pain to deal with but if you can get to them spray them down good with silicon spray on the valve and handle. That should lube them and they should open and close easily. If that does not do it you will just have to see if it clears up after a few more flushes. That should remove anything that might be caught under one of the valves.

[calliopeguy]

I have to really push on the black tank handle on my Kingston to get it to close all the way. Even then there is always a little leakage. I've had lots of 5th wheels and I've never had ONE that would be dry when I open the sewer cap. In the past I've always installed and end-of-the line valve as a final catch-all to make sure there was no surprises but my current rig doesn't have enough extra black pipe to install one. Another option is to buy a sewer pipe cap which has a sewer valve attached to it. They are readily available at most RV shops. Then you have a "final" valve which should eliminate any leakage from your system.

[Hamops]

I have the same problem all the time. I usually get about cup of liquid before it stops. This is our second 5vr and the other one did the same thing. I make sure that the drain hose is under the pipe cap before I remove it, so that any liquid still in the pipe will go down into the sewer hose.

[martinto]

Thanks for the feedback from each of you. Good observations and suggestions. Experience is the best guide to problem solving.

[geondebi]

I have had this problem on and off when the trailer was new. Then it got worse, it was the gray valve to the galley, until I changed the valve this past year. I did change the valve but in the mean time I used this and still have it on today. NOT A DROP comes out any more.

http://www.campingworld.com/shopping/item/twist-on-valve/27868</span>