Black tank slide valve

Topic: Black tank slide valve (Read 1925 times) previous topic - next topic

Black tank slide valve

May 21, 2016, 12:02:31 pm

I have a question to those who have gone this way before me. When I went to dump tanks 2 days ago, had an unpleasant surprise when I removed the outer cap to hook up the slinky. Only liquid, but evidently the valve didn't close quite all the way and let in leakage. It filled the black pipes, but didn't seem to leak any after draining a gallon or so. Cleaned the mess, hooked up the slinky, pulled the valve handle and nothing. Didn't have much resistance on the handle like it always had before.

When Kent Speers stopped by, we looked at it, he said the handle might have unscrewed from the valve, but would need to remove the top panel to look inside. I dismantled the top panel, except for disconnecting the water pump & water fill switches, and moved it to the side. Tight fit to get my big head in. The valve sticks all the way to the panel so I couldn't see any connection to the handle. It is apparently inside the valve assembly.

Now the question, Is there enough flexibility in the lower panel to pull out the panel and look/work on the valve? The exterior water faucet and the main electrical plug in is mounted on this wall. I also have the water fill hose, black tank flush valve and the grey tank handle coming through this panel. I have a feeling that the entire valve may need to be replaced, but not sure. If I do this, I am tempted to replace both black and grey valve's and possibly add the 3rd valve for good measure.

If the water faucet needs to be removed, any guess on the possibility of shut off valves for this or will I need to drain the tanks? I've looked, but haven't seen any that look like the right ones. The RV supply here isn't open till Monday and there are plenty of flushing facilities here at the park, so at least it isn't a desperate situation

Thanks in advance,
Larry Warren

Re: Black tank slide valve

Reply #1 – May 21, 2016, 12:19:28 pm

Larry, you can shut off the hot and cold water at the manoblock. There's a shutoff valve for every faucet in the coach

Re: Black tank slide valve

Reply #2 – May 21, 2016, 12:28:29 pm

Larry,
If I remember correctly, there is a set screw on top of the slide valve that secures that end of the cable. Chances are however, that it came loose because the valve is getting sticky. If the cable pull part is okay, you can replace the valve with the regular Valterra assembly by mixing and matching the parts. That is what I did when I put new valves in. Not a pleasant (or clean!) job, but the hardest part is dealing with the panel and all the "stuff" hanging from it. As regards the lower panel with the faucet, does your coach have the Manibloc assembly son the curbside of the coach? If so, there should be a shut off for both the cold and hot feeds to this faucet. I am guessing not, or you would have already seen that. If not, there should be a shut off from the tank to the pump, though it may take a long arm to reach it.
Don

Re: Black tank slide valve

Reply #3 – May 21, 2016, 01:02:11 pm

Larry,
If you disconnect any water lines to remove the panels for access be sure to use new seals/washers on reassembly.
The old seals will probably leak and you don't want that behind the panel.

Re: Black tank slide valve

Reply #4 – May 21, 2016, 01:51:21 pm

Probably no manibloc on a '96. If your pull handle goes directly to the valve blade then the plastic has probably broken and the valve will have to be replaced. Nothing a contortionist can't do easily. water tank doesn't need to be drained but if possible do drain the black and gray tanks. Good luck!

Re: Black tank slide valve

Reply #5 – May 21, 2016, 02:42:27 pm

Larry, I am sure it is same as what was on my coach so look at these pics. One shows the lock nut that needs to be undone so you can pull the handle etc out of panel (if you need too) and the other shows that you must remove the 2 top bolts thru valve to remove the "cover" that holds (clamps) the outer cable sheath so you can get to that setscrew to tighten once the cable is back into hole in valve shaft. You may be able to just loosen the two top screws and remove the 2 bolts as mentioned and slide the whole cover away to get to set screw.
Hope these help.
JohnH

Re: Black tank slide valve

Reply #6 – May 21, 2016, 08:14:14 pm

Thanks all for the replies. There isn't a manibloc so I can't shut off the water there

The only reason I wondered about the water tank was to disconnect the faucett . Thanks John D for reminding me about new washers/seals. I probably wouldn't have thought about that, till it was too late. As far as a cable goes, I haven't seen anything but the steel rod, I assume the cable is located within the valve assembly. John H, thanks for the pictures. From what I can see, my valves are somewhat different. I don't have the open frame which the rod passes thru. It appears to be solid all the way up to the valve body.

If I get the lower panel off and I can't open the valve, any suggestions on how to get the valve open for dumping without looking like Robin Williams in RV>

As always, thanks in advance for all the help and advice.
Larry Warren

Re: Black tank slide valve

Reply #7 – May 21, 2016, 11:22:57 pm

Larry, I think you will find that the set up is as I show as this seems to have been the method used by Valterra for a while and ours is a 2000 unit.
Once you have the panel off you will be able to see what needs to be done as they are very simple.
JohnH

Re: Black tank slide valve

Reply #8 – May 22, 2016, 12:23:59 am

On ours the black tank ABS black pipe runs toward street side, makes a 90 degree turn and then goes through common drain blade valve that is sandwiched between two ABS flanges with 4 bolts and nuts. Drain valve is right against back of bottom panel. We did not have the full tank problem, but we changed drain valve without removing or loosening lower panel. We permanently removed upper panel, so we could reach in (with tight difficulty) and remove 4 bolts pull out valve and put in a new one.
We did not remove electric or faucet or water lines.
Can't help with how to pull a blade, but assume you may be able to safely put an access hole in the flat part of the valve and try to reach in to pull blade. No sewage will be in the flat part. Googleing may show how others have resolved this problem.
Some motorhomes do not have the drain pull handle rod directly connected to valve because valve is in an awkward position. These use a cable connected to handle and valve. Our style valve is the most common and do not have any cables.

Re: Black tank slide valve

Reply #9 – May 22, 2016, 07:42:05 am

Larry, if the rod has pulled out of the valve,get a long shank drill bit either 1/8 or 3/16 drill down the center of the blade where the rod was, install a long wood screw and open the valve, lower coach on driver side and raise on passenger side,flush tank with plenty of water,replace both valves at the same time.

Re: Black tank slide valve

Reply #10 – May 22, 2016, 07:57:33 am

I just changed the black water dump valve on my 96' U320 last week---- it's a crappy job--- but you can do it without removing the bottom panel. The black pipe was hard plumbed and there was not enough room to replace the valve and rubber seals over the flanges without risk of breaking the tank connections, so I cut out a short section of the 3" drain pipe downstream of the valve (between the black water valve and the grey water piping) . I then used a 3" rubber clamp on drain pipe coupler from Home Depot to couple the ends. This allows you to slide the valve flanges about 2" apart to install the gaskets and valve into the flanges and then slide the flanges back together before clamping the coupler. I have used these couplers many times and they work well and last for many years. Sure made the job a lot easier. On the 96' model, the valve is mounted close to the lower panel but does have a short extension (about 1 1/2") on the operating shaft. You will have to remove this and add it to your new valve operating handle.
It's hard to get to, frustrating, and time consuming, but it can be done.

Re: Black tank slide valve

Reply #11 – May 22, 2016, 09:35:15 am

Barry, I believe that you and I have a very similar layout. What you describe sounds nearly identical. I have the water fill connection directly above the waste valve, so it hinders my view somewhat. I will remove the upper panel and see if I get enough extra room to get to the valve. If I can cut open the flat part of the valve enough to either grab the blade (assuming the connection is broken) or reattach the rod, it should allow me to slide the blade. I will just need to be at the dump station when I attempt this. If the blade attachment is broken, I might try some JB weld for a temporary fix. If I can get the tank dumped, the r&r should be fairly straight forward.

I will try this afternoon, if the showers will hold off. Thanks again to all for the replies and advice.

Larry Warren

Re: Black tank slide valve

Reply #12 – May 22, 2016, 09:43:37 am

Just saw your replies Bill & Kemahjohn. Thanks for the knowledge and guidance. Bill, once I get into the valve with an opening, I will see if I can reatach the handle. I like the idea of the long wood screw. In one of my tool boxes I have a 1/8" X 12" drill bit, so it is definitely doable. If I can get the valve working at least temporary, I will have a better time frame to do what Kemajohn suggests in about a month from now. I really appreciate the heads up on the rubber connection. I have used them in the past with great success. If you hadn't told me though, it would have turned into the way most of my plumbing jobs do with 3 or more trips to the hardware store.

Thanks a million,
Larry Warren

Re: Black tank slide valve

Reply #13 – May 22, 2016, 11:50:11 am

Larry, You can leave the end cap on and "play" around with options to get the valve open without having to tie up the dump station and feel rushed. Depending on what broke, Bill's idea sound good too. Destroying the flat part any way to get the valve open should not cause any leakage or mess at the valve. I like Kemah's idea to use the rubber connector, but we were somehow able to change valve and new rubber gaskets without cutting pipe.

BTW, we never put the top panel back, and now use the open space above the sewer pipes for spare sewer hoses and other small parts. We also have removed all trim panels over fresh water tank and also the carpeted panel over the water manifold so we can see any leaks or other problems.

Re: Black tank slide valve

Reply #14 – May 22, 2016, 12:04:02 pm

Sewer connector question
see 3rd picture

I too used the rubber "joint" sleeve when I did the electric valves a few weeks ago. I have just put in a dump line yesterday here at the house and had to cut the 3" sewer line from Guest house to install a "Y" to connect the new line to it and again used a Rubber joint. They come in handy for sure. It also ensures a proper line up for valves as they are susceptible to jamming if too tight or slightly out of alignment in a solid connected line.

Re: Black tank slide valve

Reply #15 – May 22, 2016, 04:13:17 pm

Thanks John. It is just like ones I have used on several plumbing projects on houses in the past. Nice looking job by the way.

Larry

Re: Black tank slide valve

Reply #16 – May 22, 2016, 08:35:06 pm

Figuring that Google has every answer to the important questions of the universe, I gave it a go and on my first hit found a good answer...

I Pulled the Dump Valve but the Tank Won't Drain?

◾Connect Your RV sewer hose to a dump station
◾Extend the pull rod all the way open
◾Use the saw to cut through the valve body at about the mid section.
◾Place bucket or pan under valve
◾Use needle nose pliers to reach inside the valve body and grasp the valve gate.
◾Pull gate out to allow tank to drain through the hose
◾Use rags to minimize waste leaking from cut.
◾Flush tank until water rums clear
◾Let tank drain completely
◾Replace old valve

Re: Black tank slide valve

Reply #17 – May 23, 2016, 07:50:54 am

Thanks Barry. As much as I am not looking forward to it, this is probably the fix. After reading the article, it will probably happen later this week when I move to a site with full hook ups so I can be hooked up while cutting the valve. This will give me time to find my heavy duty rubber gloves

Larry

Re: Black tank slide valve

Reply #18 – May 23, 2016, 08:57:44 am

Larry, here is a picture of what our plumbing looks like with the panels removed. The panels were not easy to remove but it makes the rest of the job much easier. You can see where the cable pulls are clamped in the upper frame and where the cable wire connects with a set screw. Yours might be different but probably not much.

Re: Black tank slide valve

Reply #19 – May 23, 2016, 11:09:26 am

When I replaced my valves, one of the push/pull cables had been cut too short. Since I did not have a replacement, I reused that cable, but it is still (almost) too short.

Does any one know where I can get a longer cable? I thought of using a piece of music wire, but did not know what size to buy. Anyone solved this problem previously?

Thanks,

Trent

Re: Black tank slide valve

Reply #20 – May 23, 2016, 11:26:39 am

Thanks for the picture Roger. Mine is slightly different. My black tank valve is after the 90 deg elbow. Both valves use a solid rod to attach the handle. The black tank valve pushes up tight to the lower panel with a hole for the handle to stick thru. I need to figure how to take the lower panel off or at least loose. The service tech at the rv supply house showed me where the end cap on the valve will pop off. It would make it where I can see what is down there. It would make it where I could rethread the handle if that wasn't broken or possibly grab the top of the blade from the end instead of cutting the valve apart. I will update as I go.

Thanks again, keep em coming.
Larry

Re: Black tank slide valve

Reply #21 – May 23, 2016, 11:28:49 am

Trent, I used a local RV repair place in San Diego but I'm sure Camping world would have them

Re: Black tank slide valve

Reply #22 – May 23, 2016, 12:35:13 pm

Trent,

You can get new handles and cables. Here is a six foot one, There are 8 ft as well and may be shorter.

Amazon.com: Valterra TC72 72" Replacement Flexible Cable: Automotive

Valterra TC72 72" Replacement Cable

As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.

Re: Black tank slide valve

Reply #23 – May 27, 2016, 11:04:53 pm

I had the same issue on my black tank and I used the Thetford Aqua Kem
and after three dumps the valve stopped leaking. I think it cleaned and lubricated the seals.

Re: Black tank slide valve

Reply #24 – May 28, 2016, 09:12:53 am

Just had another Rube Goldburg thought. Has anyone tried holding the anvil end of a reciprocating saw (without a blade in it) up against the black tank and holding the trigger down? Wouldn't the vibration transmit enough to the tank to loosen "stuff" from the tank?
Granted, some tanks are inaccessible, but others have an area open.
Sure would beat ice cubes sloshing around and having to stress out the coach with swaying and panic stops.

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