Black tank "dump" slide valve

[2012FB]

Since new the black tank dump valve has always had a bit of resistance to fully close, but told it felt normal when I complained. Now it has just stopped about a 1/4" of full closed. We are very careful and have I have never had to replace one is 20 years with 4 different trailers. I assume drop the pan and replace the valve assembly. I just do not have any other ideas at this point. I filled the toilet full and with the black tank flush line running full would then flush the toilet but still it refuses to seat. Hard debris from the factory install or bad seal face?? Suggestions?

[withidl]

Try "back-flushing" with the grey tank to dislodge any obstruction at the valve seat. To do so fill the grey tank to maximum, fully open the black valve, raise the stinky slinky above the grey tank level and hold it there while fully opening the grey tank valve so that the grey water enters the manifold and reverse flows into the black tank, then close the grey valve. At this point you might try to also close the black valve to determine if any obstruction was dislodged. Lower the stinky slinky and open the black valve to drain the black tank. Repeat several times.

If that doesn't work you might try feeding a water hose into the manifold.

[xrvr]

Do not really know but, dies the handle screw in and out? If so you may try screwing it out some, or in I do not remember, to see if that gives enough extra rod to push the handle in. Jim

[2012FB]

I brought the trailer to the shop and put the hose up the outlet as suggested. Moving the valve back and forth slowly while spraying it finally went past the catch to full closed. The valve is still very stiff to operate, as it has been since new, but it is now going fully closed again. There was nothing at all that came out of the water flush so I still just think it is a bad seal. Maybe water on the back side of the valve/slide seal was all it needed. Thanks for the suggestions!!

[idroba]

You still may be under warrantee and you should have a record of your original complaint about it. I would try to get it fixed by AS. On my new 20' FC the valves slide like a hot knife through butter. Don't take the old "we don't want to fix it, so it is normal" as an answer. Demand to see other units which are as stiff as yours apparently is. They won't be able to show them to you, I would bet. It is not going to get better by itself.

[rgarza348]

We had a similar problem with our 2014 27FB. We've only used it a few times but noticed that open the black water valve was okay, but closing required a bit more effort. I noticed the rod on the T-handle was rubbing against the sheet metal. I brought it up to the dealership, they contacted Airstream. Airstream advised to trim away the sheet metal where the rod was rubbing. Appears to function fine now.

[SilverCabin]

Here's my story with the dump valve:

When we picked up our new 2014 in April and went through the dealer inspection, I asked if they had serviced the toilet/black tank with chemicals. They said they had, but they hadn't. During the inspection we flushed the toilet repeatedly with water from the pump and city water to make sure everything was working. When we completed our inspection we pulled away and drove a short distance to a KOA that we frequent, and get a good price for our loyalty too.

I went to hook up the sewer hose and when I removed the cap, a good quantity of clear water came out...put that on my list to check again. Turns out, that was the water we had put in the toilet, no chemicals, no color.

At the end of our first outing, we dumped and flushed both tanks, and put chemicals in the black tank so it would be ready for our next outing, put the cap on the drain, and parked the Airstream for a few weeks. About a week or two later, I went out to change the drain cap to one that has a hose connection. When I removed the cap, about a cup of blue water came out...obviously from the black tank.

What I discovered, was that the way the dump handle was adjusted, when the spring clips were engaged, the valve wasn't fully closed, allowing the fluid to leak out. There are two adjustments. One to let the valve fully close, and one to let the spring clips hold the valve fully closed. I made those adjustments, but still had a little dribble of blue water, when I checked a couple of weeks later. My suspicion was that some debris had leaked into the valve seat during our first outing and wasn't letting it seal completely.

My fix was to fill the black tank with water several times, and cycle the dump valve several times while the tank was draining, especially letting it rinse through a partially opened valve to get some water flow over the seals that may have been fouled with debris. This seemed to do the trick. After setting for another couple of weeks, when I remove the cap all is dry inside.

Randy


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[Foiled Again]

I always thought that "tank valve lube" stuff was BS - but maybe not. I'm sure the valves are neophreme but even so if they sat dry from the factory to the dealer to you... maybe lubing them up will make them more supple and let them seal better. Worth a try... and cheaper than hauling it back to the dealer for warranty work.

Paula

[silver27]

SilverCabin - we are having that EXACT same problem with our 2014 FC. Thanks for sharing that.