Black Tank Valve Not Closing Completely

Mark and Becky · 06-05-2015, 09:34 PM

I recently noticed that our black tank is draining with the the valve control in the closed position. The valve control feels like it's working normally, but when the valve control is pulled to drain the tank, nothing is coming out of the hose. We have been at a full hook-up site for a month, and the tank is not even close to full, leading me to think the drain valve is either wide open or partially open allowing the tank to remain drained. Any ideas as how to get it closed again and working properly?

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ColoradoRick · 06-05-2015, 09:44 PM

Quote:

Originally Posted by Mark and Becky

I recently noticed that our black tank is draining with the the valve control in the closed position. The valve control feels like it's working normally, but when the valve control is pulled to drain the tank, nothing is coming out of the hose. We have been at a full hook-up site for a month, and the tank is not even close to full, leading me to think the drain valve is either wide open or partially open allowing the tank to remain drained. Any ideas as how to get it closed again and working properly?

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More than likely has a little something stuck in the mechanism.

If you have a flush valve, you can connect a hose and fill it up then flush it a few times...hopefully will clear the blockage. (My gray tank has a little block but flushing it a few times seemed to fix it.)

While emptying it, open and close the valve a few times while water is flowing out.

Good luck!

shughey00 · 06-07-2015, 11:32 AM

We have an older 34ckts that had a slow leak from the black water tank.

I had used the tank flush built in to the rv until the water ran clear trying to fix it. Still leaked....well I assumed it was a slow leak because unlike you ours would have water in it when I dumped after 5 days but nowhere near what I would expect.

I ended up going to wally world and getting the camco reverse flush adapter MAINLY because it is clear...goes on the dump and I could see for sure if I was slow leaking. Sure enough I could see for sure now it was a slow leak and more so now I can see when it was fixed.

Also I can see when I use the tank flush system when the solids stop. Amazing what gets left behind even when you dump a full tank.

I decided to use the reverse flush function since it had it even though the built one I had used multiple times.

Not expecting much I turned it on. Well after about a minute gunk and solids started coming out. Ran it for maybe ten minutes. Never had a problem since.

All I can figure is that the built in sprayers are not aimed at or directly spraying on the valve area and I must have had some seriously dried or stuck solids. SInce the cheapo Camco one sprays a jet nozzle spray back up the drains it must have cleared whatever was built up around the valve.

Supposed to work best if it is straight shot from the dump to the tank valve but mine isn't...still worked good. Still use it once a month and still washes stuff out the built in does not.

At least with it being a clear fitting I can see whats coming out.

Just my experience.

Mark and Becky · 06-07-2015, 12:17 PM

Going to Camping World tomorrow! Thanks for the info everyone!

hillsdaletc · 06-07-2015, 12:26 PM

You may also closed the valve and caught some tissue in the groove of the slide valve. This stops the slider from sealing all the way into the seal. If this is a fairly new unit, it is VERY common to find the round blank from the hole saw still in the tank and it gets washed around and down to the drain. If it's the smaller vent blank it can get caught easily.

donanddona · 06-07-2015, 12:44 PM

In an emergency I have this till I get a chance to fix it.

hillsdaletc · 06-07-2015, 01:27 PM

Mark, while there pick up some holding tank " digester " by Thetford. It works great to clean stubborn deposits and tissue from your tank and sending units. Thetford makes most RV toilets.

FrankinKane · 06-08-2015, 11:57 AM

This may help in the future. I've been RVing for 7 years and I have a routine when dumping the black tank. First I use a clear adaptor just before the sewer hose and while flushing I can see when things run clear. I also fill and dump the toilet while flushing 4 0r 5 times at least every other time I dump. Have never had a problem with the tank valve. You'll be surprised what filling and dumping the toilet loosens up.
Good Luck and Happy RVing!

KAS · 06-08-2015, 12:27 PM

Thanks for everybody's input! I didn't know there were items available to help in flushing out the tanks. I just ordered the Camco 39062 Dual Flush Pro Holding Tank Rinser with Gate Valve from Amazon, this looks like the perfect solution. You can see if anything accumulates behind the valve when the tanks are closed and the tanks leak and you can rinse out the tanks without a mess. I used to either run a hose into the toilet to flush out the tank (hit or miss) or I would shove a water hose up the drainpipe to rinse out the tank (messy). The Camco 39062 Dual Flush Pro Holding Tank Rinser with Gate Valve seems to be the perfect solution. I'll get a chance to try it out when I go camping next week.

Harkerr · 06-08-2015, 12:31 PM

Could be toilet paper. Tends to stick in valve seal. Try the flushing described. Use rv toilet paper. The clear adapter is critical to see how flush is going.

Harkerr · 06-08-2015, 12:33 PM

I fought this for several years. I ended up putting in an electric valve. No problems since

Pierre Allard · 06-08-2015, 02:10 PM

Quote:

Originally Posted by Harkerr

I fought this for several years. I ended up putting in an electric valve. No problems since

Where did you get electric valve?

Hutch333id · 06-08-2015, 06:34 PM

I had the same problem with my black and grey tank valves when we took delivery of the new 38FL straight from the dealer. Turns out there was some manufacturing debris stuck in the valve groove which the dealer removed when they replaced the gates. Apparently, this is not uncommon. Warranty covered the cost of my repairs, thankfully.

Richard & Diane
2014 Cedar Creek 38FL
With an F350 DRW

magpi26 · 06-08-2015, 07:39 PM

Brand new Sabre had trimmings of linoleum stuck in the valve when it was delivered. I also had lots of wood chips and carpet pieces when I flushed it on the first trip last summer.

cpaulsen · 06-09-2015, 06:20 AM

Had that problem once.....flushed and filled many times...and used the extra Valterra valve. Added some Riddex to the tank and waited till it was full before dumping again....and did not have any problems again. Now I add a little Riddex after dumping.

Rdeemat · 08-01-2015, 03:53 PM

I have a 2007 37ft Cedar Creek 37RDTS, (purchased brand new), that has 3 Drain Master Electric Dump Valves. I don't trust these valves to work properly so I keep them open permanently. Only one, (gray galley tank) of the three is visible and accessible. The other two are buried so deep in the belly of this beast it would cost several thousand dollars for a repairman to come out and disassemble the whole undercarriage to find and repair or replace one. I'm permanently parked with wheels off the ground and no tow vehicle so taking it in for repair is out of the question. I have a Clean Dump Macerator that holds everything back until ready to dump, (about once or twice a week) and so far after three years all is well. I've tried getting a layout of the unit shortly after I bought it but FR Mfg. says sorry no can do. Dealer also says tough luck chuck, you bought it, you own it. Any comments?

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