Black Water Maintenance

[Buddy]

Dump Valve Maintenance


You're winding up a great weekend in your RV, and you pull up at the dump station to take care of the "necessary" duty of dumping your tanks. You dig out the sewer hose, take off the sewer cap, and out comes the liquids (and solids) that your dump valve failed to hold in the tank!

When this happens, don't jump to the conclusion that your dump valve has failed and needs to be replaced. More than likely, it is material that has become trapped in the groove where your dump valve seals.

The dump valve slides open and closes in a groove that has a rubber O-ring on each side of a nylon flat plate. What often happens is this: If you slide your valve closed while the tank is still emptying, toilet paper and solids can get worked into the groove--keeping the slide plate from making a proper seal.

Before you leap into an expensive dump valve replacement, try this easy procedure for cleaning the groove and O-rings. First, fill your holding tank completely with a mixture of water and dish soap (the dish soap acts as a lubricant for the rubber seals around the dump valve slide plate). As the water is emptying, repeatedly open and close your valve. This action works the solids loose and the running water washes them away. You may have to repeat this process a couple of times.

[subdoc4]

Originally Posted by Buddy

Dump Valve Maintenance


You're winding up a great weekend in your RV, and you pull up at the dump station to take care of the "necessary" duty of dumping your tanks. You dig out the sewer hose, take off the sewer cap, and out comes the liquids (and solids) that your dump valve failed to hold in the tank!

When this happens, don't jump to the conclusion that your dump valve has failed and needs to be replaced. More than likely, it is material that has become trapped in the groove where your dump valve seals.

The dump valve slides open and closes in a groove that has a rubber O-ring on each side of a nylon flat plate. What often happens is this: If you slide your valve closed while the tank is still emptying, toilet paper and solids can get worked into the groove--keeping the slide plate from making a proper seal.

Before you leap into an expensive dump valve replacement, try this easy procedure for cleaning the groove and O-rings. First, fill your holding tank completely with a mixture of water and dish soap (the dish soap acts as a lubricant for the rubber seals around the dump valve slide plate). As the water is emptying, repeatedly open and close your valve. This action works the solids loose and the running water washes them away. You may have to repeat this process a couple of times.

When I read this, I thought you were reporting my experiences!
I ended up purchasing another gate valve that fits on the end where the cap goes. After "dumping", I can close the external valve, put on the cap, and no more residual "fluid" dripping out when I hook up the next time.
By closing it, you can open the "gray" valves and it will equalize both gray tanks to maximize their size.

Thanks for the "soap mixture lubricant" tip!

[SueMar]

Are others having problems with the black tank valve? We've had ours replaced twice in the 6 months we've had our rl.

[atom ant]

Originally Posted by SueMar

Are others having problems with the black tank valve?Â* We've had ours replaced twice in the 6 months we've had our rl.Â*

just curious, does the cable seize or break, or is it something else?

[Dave&Ginny]

As my cables break, I'm going to be replacing them with the electric valves.

[Adamsvr]

We just had our cable break away at the handle mechanism. Had it replaced. While the tech was connecting the cable to the valve, the valve assembly fell off the black tank. The down angle of the black tank was too steep at about 10 degrees for the horizontal 3" PVC exit tube to connect. Apparently they weren't glued. Since the valve was already off, had the tech replace it as it as leaking and add a 6" rubber connecting tube to the valve.

[subdoc4]

Are they More dependable?
(The electric ones).Edited by: subdoc4

[SueMar]

The first time, it was the valve itself -- just wouldn't close. The second time, the cable kinked

[UNDRPSI]

I like the electric valve idea Dave. Our gray tank valves are starting to get tight. Are these a cable inside of a covering or are they inside of a small pipe? If the cables inside of a cable cover or case then I think I’m going to try some WD-40 and see if it will work its way to the end to see if that will free it up a little. I want to wait a few weeks on upgrading to the electric valves.

[Adamsvr]

The cable assembly is covered with a plastic housing covering a sprial metal housing and a wire to pull the valve. The cable is connected to the handle assembly with a compression fitting. No set screw. While you can spray lubricant onto the first three inches of the wire, there is no way to get it down the length of the wire.

[UNDRPSI]

Originally Posted by Adamsvr

The cable assembly is covered with a plastic housing covering a sprial metal housing and a wire to pull the valve. The cable is connected to the handle assembly with a compression fitting. No set screw. While you can spray lubricant onto the first three inches of the wire, there is no way to get it down the length of the wire.

Adamsvr
So what your saying is there is no real way to get lube down the full length of this cable then? Looks like I may end up doing this sooner then later. One thing I hate and I think it was a bad design is that in order to leave the valves open you have to leave the door open and if the wind is blowing it just bangs so I put on a foam softener on it but I just don’t like leaving the door open. I think this is where water gets into the cables and causes trouble down the road. I think there was plenty of room that they could of used a deeper box to install the valves in so we could at least keep the door closed.

[atom ant]

You can't close your door with the valves open?

[UNDRPSI]

NO Sir! So I leave them closed most of the time. But we have to leave them open when doing laundry. So we have to leave the door open. And there is always a nice breeze here in TX.

[Oriana]

Originally Posted by atom ant

You can't close your door with the valves open?

Negative on closing the door with any of the valves open.

With the valve modification we have on the FL, to use both grey tanks you have to have both valves open. If we want to close the door we have to close the valves, which means we can onlyuse 1 of the grey tanks.

[atom ant]

Originally Posted by Oriana

Â*
Negative on closing the door with any of the valves open.
Â*
With the valve modification we have on the FL, to use both grey tanks you have to have both valves open. If we want to close the door we have to close the valves, which means we can onlyÂ*use 1 of the grey tanks.

I guess I never really tried. There goes the theory of leaving the gray open for the week.

This tanks are huge compared to what I had before, maybe it won't be a problem.

[homeguy]

Are there only certain models where the door has to be left open to keep the valves open? We have a RL and I have no issue closing the door. As a matter of fact, I keep the outside shower hose connected to flush tank so that after I dump the black tank, I just turn on the cold water and let it run for 10 - 15 minutes. No issue closing the door at all.

[Adamsvr]

I think that depends on your model of Redwood. On our 2012RL, we can open the valves and close the doors.

Regarding lubing the five/six foot cable... all you can do is spray silcon or graphite on the first three inches of the handle assembly and hopefully some gets to the wire. But most likely, if the handle is hard to pull, it is most likely that the rubber gaskets on the gate valve have dryed out, or have debris in them. I endorse other recommendation's of pouring some cooking oil down the drain to lubricate the valves.