Black tank flush issue

lightning79 · 07-23-2013, 10:30 AM

Hello friends,

Had an issue with my black tank flush this morning. I hooked up a hose to it to flush it out. I had the black tank valve open, and I THINK I had the grey valve open, too. Well, when I turned on the hose, water immediately started leaking out the side of the trailer. I quickly shut it off, and went inside. There was about half an inch of water on the floor of the trailer under the bathroom sink where the flush valve was hooked up. After my blood pressure went through the roof, I got the trailer dried out. There wasn't much water, as I guess I had quick enough reflexes to get it turned off, but it's frightened me.

Now, I wish I could remember if I had the grey valve open or not, it all happened so fast. Maybe a leak in the flusher lines? Any ideas as to what's happened?

Kevin

lightning79 · 07-23-2013, 10:35 AM

Forgot to mention, there was only fresh water that I had to wipe up, nothing from either of the other two tanks.

Festus2 · 07-23-2013, 10:48 AM

lightning79 -
Like many others who have experienced exactly the same problem, the cause is almost always the same as well --- a faulty check valve in the black tank flushing system.
It has probably cracked or simply "exploded" inside and now you have ended up with water everywhere. Doesn't help but you are just one of many.

Check the search feature and find out what others have done to solve this problem. If it is due to the check valve, replace it with a brass fitting or make an alternation in the system to bypass this altogether. There are numerous posts/threads -- type in Black tank flush or black tank flush check valve or something similar.

If you can't find any posts that will help you out, get back to us.

Get back to us anyway and keep us posted as to what you found and how it was fixed.

lightning79 · 07-23-2013, 01:10 PM

Thanks, Festus, I appreciate your advice, and hearing that i'm not the only one. I love this trailer, and I certainly don't want to do anything to hurt it!

I'll do a forum search for the topics you've mentioned.

Kevin

therink · 07-23-2013, 01:26 PM

Same happened to me but fortunately it was during my pre-delivery inspection. One of the barbed hose fittings was loose on the vacuum breaker valve. Has worked fine since then.
As mentioned, very common problem.

labs4life · 07-23-2013, 01:30 PM

FWIW, I recently swapped my "vacuum breaker" for a brass gate valve. Works perfect and no chance of EXPLOSION!!

Festus2 · 07-23-2013, 01:53 PM

Kevin -
One thing I forgot to mention, is that this vacuum breaker valve may have cracked because, during the winterizing process, you forgot to ensure that you had the pink stuff in that system, it froze and cracked. Or you didn't blow out this section of plumbing.

This part is not the best of quality - you might just want to replace it with something better if you can find it or do as labs4life suggested.

lightning79 · 07-23-2013, 05:09 PM

I'm sure I didn't have the pink stuff in the black tank flusher lines. How would I go about getting it in there?

**JRTJH** · 07-23-2013, 05:15 PM

Quote:

Originally Posted by lightning79

I'm sure I didn't have the pink stuff in the black tank flusher lines. How would I go about getting it in there?

Some people use the outside shower to pump it into the black tank flush fitting, others just blow it out with air and then use a hand pump to put some RV antifreeze in the line. Some tow the RV to Florida or some other "warm winter storage area". Others just say "oops" when they get water leaking out the side of their RV

therink · 07-23-2013, 05:25 PM

I have always blown mine out with air. It. Takss about 30 seconds. All you need is a $2 air chuck adapter fitting. Running antifreeze from outside shower works too.

lightning79 · 07-23-2013, 05:32 PM

I"d say that Festus has hit the nail on the head regarding my issue, I know I didn't have any antifreeze in their over the winter. I've searched these forums and found a few things, but I"m having a hard time figuring out what the check valve and the vaccum breaker valves look like.

Well, I don't use the toilet very often, and have ever only used it for one thing and not the other, so it sounds like I don't need to be in a rush to get this fixed.

Silly me, so this is a result of not fully winterizing the trailer, and I was sure I followed the winterizing guide the dealer gave me!

Thanks for all the responses!

Kevin

lightning79 · 07-23-2013, 05:33 PM

Quote:

Originally Posted by therink

I have always blown mine out with air. It. Takss about 30 seconds. All you need is a $2 air chuck adapter fitting. Running antifreeze from outside shower works too.

How would I run antifreeze into it from the outside shower?

Festus2 · 07-23-2013, 06:03 PM

When winterizing, I ensure that the black tank flush receives a good shot of the pink stuff. I bought a hand pump at CW which I use for the black tank flush and the FW hose intake. One end of the pump goes into a container of pink stuff and the other end screws into the female hose fitting at the black tank flush and the FW hose intake.

As far as the outside shower is concerned, it is part of the general FW plumbing system and is like any of the interior faucets - except that it is on the outside. I do not think it is connected in any way to the black tank flush so I treat it as something completely separate.

You can, if you wish, blow air into the system, use the pink stuff or do both - blow the lines out with air first, then add RV antifreeze.

lightning79 · 07-23-2013, 06:38 PM

Festus, you're a great source of information, I'll get one of those hand pumps wherever I can find one.

So how easy is it for me to fix the broken valve? Probably better for an RV service place to do it? They'd be better at finding the exact source of the leak than I would, I can't really figure out what the faulty part even looks like!

**JRTJH** · 07-23-2013, 06:41 PM

First use compressed air to blow out the black tank flush system, Then think about the following:

When you turn on the hot or cold water faucet at the outside shower, it will run whatever is in the lines out of that faucet. So, when you're pumping antifreeze through thte cold and hot water lines inside the RV and then to each of the faucets, as you turn on the outside faucet, it will flow pink. If you plug in the hose, adapt it to a 3/4" male garden hose fitting, you can screw it into the female black tank flush fitting and pump "pink stuff" into the black tank flush system. You won't be able to tell if you've filled the entire flush system line unless you open the black tank valve and observe pink flowing out of the tank. Then you can be assured that the anti-siphon valve is protected.

I find that using a hand pump is much easier and faster, however I always ALWAYS use air to blow all the water out of the line beforehand. That way, there's no doubt when I hear liquid flowing into the black tank, it's antifreeze.

lightning79 · 07-23-2013, 06:46 PM

Thanks, John, I'll be doing all that.

OKay, starting to make progress, this looks like the piece that is the culprit:

So if I replace this part, I should be good (obviously looking at all the lines to check for any other leaks?)

Does this part come in brass, is this the vaccum thingy/check valve thingamadoo that's been the source of the trouble? It was under this that my travel bag for my personal cleaning stuff was full of water!

Thanks so much for everyone's patience!

Kevin

Festus2 · 07-23-2013, 06:53 PM

Kevin -
One way to find out if that is the culprit, is to connect a hose to the black tank flush and turn it on. Best to have two people do this - one to operate the tap at the hose and the other to watch for any water leaking or coming out of that vacuum breaker. Keep lots of towels handy to wipe up any water.

The minute you see water coming out, get your partner to immediately shut off the tap.

Not very scientific, but you will know for sure if that is where the water is coming from and that is the source of the problem.

lightning79 · 07-23-2013, 06:55 PM

From what I can see, that is one of the few pieces on the black tank flush line, as after it the line pretty much goes right under the bathroom sink and down towards the black tank. what is that black part called? It looks like plastic, can it be replaced with a brass fitting?

Anybody sick of me bugging them about this yet?!

Kevin

**JRTJH** · 07-23-2013, 07:30 PM

You still have a few posts to go before you get told to "go to bed" LOL

As for the pic you posted, Yes that is the black tank anti siphon valve.

Here is a picture of "roughly" what the entire system looks like:

There are brass anti siphon valves available at Lowes or HD. you will probably have to do some rearranging of the PEX lines/fittings to connect the brass valve. Remember, you still need to winterize it as the fittings may still freeze and crack. The actual PEX tubing is pretty flexible and probably won't be damaged by freezing, but the fittings may not survive the winter.

GMcKenzie · 07-24-2013, 09:55 AM

Having never given this part of the trailer any thought, thanks for asking all these questions.

Something to add to my winterizing. Guess I've just been lucky for the last 2 winters.

You may also like: