Sundance 3400QB Black Tank Leak

ncrzrbk

Well-known member
Getting the camper ready for our first trip. Noticed that the Blank Tank valve leaks. Any ideas or suggestions on how to fix this? I don't have time to run to the dealer for this repair. I put the cap on the drain and then later take it off. Water pours out of the cap. Hooked up the black tank flush and closed the valve. There is a steady stream of water coming out. I noticed when I first flushed it today there was a lot of black junk when it drained. Is it possible some of this got caught in the valve? Any help would be appreciated!!
 

JohnDar

Prolifically Gabby Member
Getting the camper ready for our first trip. Noticed that the Blank Tank valve leaks. Any ideas or suggestions on how to fix this? I don't have time to run to the dealer for this repair. I put the cap on the drain and then later take it off. Water pours out of the cap. Hooked up the black tank flush and closed the valve. There is a steady stream of water coming out. I noticed when I first flushed it today there was a lot of black junk when it drained. Is it possible some of this got caught in the valve? Any help would be appreciated!!

The best temporary fix is to put a Valterra twist-on valve on the sewer connection and then cap that. Then when you need to hook your sewer line, you won't get mugged by sewer trout.

There is a good probability that something, like TP, got caught in the valve seat opening, preventing the valve from fully closing. You could try backflushing it a few times to see if you can dislodge it. Let the water sit for a few minutes before draining it back out to try and loosen it.
 

olcoon

Well-known member
We also had that problem on our Elk Ridge. Took it to the dealer about 3 times to get it fixed under warranty & finally they got it fixed...for a while. I bought one of these and it took care of the problem. If you get one make sure the valve handle is pointed to the rear, so it won't vibrate loose going down the road. I used some insurance & put Gorilla Tape on it & haven't had a problem. As far as why it's leaking, there could be some TP or other debris stuck in the valve, or the infamous plastic disc that fell into the tank when they drilled the hole to install the pipe. We also had that problem, couldn't get the valve closed & when I was able to tear into the problem, it was that plastic disc stuck in the valve & it wouldn't close. About the only way to get it is to drop the underbelly & remove the valve. Not fun, make sure the black tank is flushed out REAL good because you will get some liquid on you. Make sure you get the gaskets on there correctly as if you don't they will leak. I had ours leak several times, & finally with some help from other Heartlanders at a rally, I cut out a section of the drain pipe, installed the valve then put a rubber sleeve over the pipe where I cut it. It's been almost a year and so far no more leaks. Good luck!!!
 

danemayer

Well-known member
Hi ncrzrbk,

If it wasn't leaking right from the beginning, it's very possible you have paper jammed in the gate valve, keeping it from closing completely. Sometimes you can clear this out with repeated flushing and back-flushing. There are two accessories that will help and also will be helpful in normal use.

First, get an external twist-on gate valve. Until you get the leak resolved, this will let you continue camping without a horrible mess every time you remove the cap to connect the sewer hose.

Also get a clear sewer outlet extension with hose fitting. This will let you see what's coming out the sewer line so you know when you can stop flushing the tank. You can attach your black tank flush hose to this fitting to back flush the line back up to the tank.

Here's a link to a combination unit.

What I usually do is dump the black tank when it's nearly full. After opening the dump valve, I'll turn on the water to the black tank flush. I'll let it run until the water is clear. Then I close the external gate valve and let the black tank flush fill the tank for 4 minutes. It's very important to not get distracted while doing this or you'll have BIG problems. Open the external gate valve and let the tank flush again. I'll repeat this several times and will usually get paper and sewage for at least three cycles. Sometimes there's a blockage that slows the water coming out for as much as a minute, but it always breaks free.

Don't close the black tank valve until you're sure there's no more paper still in the tank. Then add a few gallons of water through the black tank flush. You never want to leave the black tank empty or you'll have solids build up on the bottom of the tank.

The external gate valve will keep the black tank from leaking all of its water while you have a leaky dump valve. Until you resolve the leak, add a few extra gallons of water after dumping the black tank. That'll compensate for the water leaking toward the external gate valve.


On edit: I re-read and see you haven't taken your 1st trip yet. So this is either a defective valve, or factory debris as Roy mentioned. The external valve will let you manage it until you get back to the dealer. Probably a good idea to call Heartland Customer Service at 877-262-8032. Have your VIN # ready. Let them know you haven't used the bathroom yet, but the black tank doesn't hold water. Ask them to log that so there's no confusion when the dealer goes to do the warranty work.
 

ncrzrbk

Well-known member
I understand the whole TP thing but this camper was bought new and the toilet system has never been used. I was getting it ready for our very FIRST trip and had just dewinterized it when I noticed this valve not closing all the way.
 

ncrzrbk

Well-known member
By the way, Thanks for the helpful information. Flused the thing out enough to fill a swimming pool. However, still has the leak. Guess a trip to the dealer is order but I will take everyone's advice and get the extra valve.

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