Cougar 364BHL Rear Black Tank Flush

Jbro · 05-15-2022, 06:33 AM

Wondering if anybody can help with this as I can't find anything in my manuals or from watching videos on you tube.

Model: 2022 Cougar 364BHL

I'm looking for the black tank flush for the rear black tank. I have one labeled tank flush, which I was told was for the front black tank. There is a similar looking port to the right of this. I'm guessing this might be the rear flush, but would love confirmation before I screw something up. Anybody out there know for sure?

The unlabeled port is in the photo below with the red arrow pointing at it.

**chuckster57** · 05-15-2022, 06:51 AM

Welcome to the forum

When you bought your trailer, did you get any kind of walkthrough showing you what everything was?

You can hook a hose to that connection, turn in the water and then look at the monitor panel, watching for an indication that the level is rising in the rear black tank. Just don’t let it run any longer than needed.

Jbro · 05-15-2022, 07:06 AM

Yes, I did get a walkthrough, but this is my first camper and there was so much information that it was overwhelming. I wasn't even sure how everything was plumbed at the time of my walkthrough, so wasn't smart enough to ask. I'm pretty sure he only covered the labeled port and said it was for flushing the black water tank.

That is a great idea regarding watching the monitor panel. If I can't get an answer before the camper is delivered on Wed, I will do that. Thanks!

**JRTJH** · 05-15-2022, 07:27 AM

There is another thread, identical question on a similar trailer posted by a different member. Thread located here: https://www.keystoneforums.com/forum...ad.php?t=51453

**sourdough** · 05-15-2022, 08:39 AM

I figure it's the back tank flush port. Don't have 2 black tanks but all the trailers I've owned with a black tank flush had that little sticker right above the flush inlet. In this case it's right between the 2 with no label for the one on the right. Certainly not scientific or definitive but enough to "figure" that's what it is. Instead of watching the monitors and let water run into an enclosed tank you could just pull the dump handle on the back black tank and turn on the flush - water should come out.....unless it needs to be dumped.

Jbro · 05-16-2022, 04:27 PM

Well I sent an email to the service manager at the RV dealer where I bought it, and he said "he thinks" it's the port for the rear black water tank. I guess it probably is, but I'm still going to verify with the methods suggested above before trusting.

lonerider98 · 05-16-2022, 06:18 PM

Yes that is your rear tank flush. I have the same trailer!

Jbro · 05-16-2022, 11:52 PM

Quote:

Originally Posted by lonerider98

Yes that is your rear tank flush. I have the same trailer!

Awesome, thank you for confirming!

Jbro · 05-22-2022, 06:19 PM

Quote:

Originally Posted by lonerider98

Yes that is your rear tank flush. I have the same trailer!

Another question for you, if you don't mind? Can you confirm that there is only the one gray water tank valve that is located in front left control panel in my picture above?

I know there is a second black water tank valve behind the tires right next to the rear waste discharge, but in my walkthrough they said there is only the one gray water tank valve despite there being two gray water tanks.

The reason I'm asking is that water comes out of the front waste discharge even when the gray water valve located in the front control panel is closed (pushed in). Doesn't seem to matter where I run the water, front bathroom sink, kitchen sink, rear bathroom sink, it runs right out of the front discharge pipe despite the valve supposedly being closed.

Since I'm brand new to this RV thing I'm just trying to sanity check this before pursuing a warranty repair.

lonerider98 · 05-22-2022, 06:53 PM

You have two gray water and two black tanks. the valves in the front compartment controls the first black tank and the bathroom gray tanks. There is a pull valve behind the tires for the 1/2 black tank. Now there is suppose to be a gray tank valve just in front of the tires. But mine is hidden in between the tires not mounted where it's suppose to be. So look for it between the tires. to shut it off.

Jbro · 05-22-2022, 07:00 PM

Quote:

Originally Posted by lonerider98

You have two gray water and two black tanks. the valves in the front compartment controls the first black tank and the bathroom gray tanks. There is a pull valve behind the tires for the 1/2 black tank. Now there is suppose to be a gray tank valve just in front of the tires. But mine is hidden in between the tires not mounted where it's suppose to be. So look for it between the tires. to shut it off.

Thanks! I'll be back out to camp this week at some point and will look for it.

lonerider98 · 05-22-2022, 07:02 PM

Your Welcome!

Robear · 05-26-2022, 08:20 AM

Hello, since you all are discussing black tank flushing, I have an issue with my 25RET cougar.
I went on a 3000 mile trip this month and half way through the journey I hooked up the hose to flush the black tank after draining, which I have done many times before. Turned on the water and no spraying sound in the black tank. Strange, so I thought maybe the campground water pressure was too low. Added laundry soap and water to slosh around for the trip home. Now that I’m home, I tried it again and no water is getting to the tank flush sprays. It’s like it’s clogged or something. Could a hose be kinked somewhere, or some hidden valve accidentally closed from the trailer shaking on rough roads?

**JRTJH** · 05-26-2022, 05:12 PM

Robear,

The plumbing lines for the black tank flush system is all PEX. If it wasn't kinked before, there's almost no chance that it would suddenly "kink and stop flowing". You didn't say whether the black tank was filling just that you didn't hear water flowing. If the tank is relatively full (over half full) you probably wouldn't hear the nozzle "spraying against the tank walls" since it would be underwater. You should hear the anti-siphon valve "buzzing" under the vanity, but often from outside, you can't hear or can barely hear that valve.

If it was working previously, then it should still be working. Dump the tank, let it drain completely, then turn on the flush system and watch the sewer hose to see if anything is flowing. You can, if you watch closely and don't walk away, close the black tank valve for a few minutes, then open it and see if you get a "gush of water" as you open the valve.

But, to answer your question, "Maybe the line is kinked". Probably not, since it's rigid PEX tubing and if it has been working in the past, on a 2013 trailer, there's almost no chance that the PEX suddenly kinked.

Robear · 05-26-2022, 09:17 PM

Quote:

Originally Posted by JRTJH

Robear,

The plumbing lines for the black tank flush system is all PEX. If it wasn't kinked before, there's almost no chance that it would suddenly "kink and stop flowing". You didn't say whether the black tank was filling just that you didn't hear water flowing. If the tank is relatively full (over half full) you probably wouldn't hear the nozzle "spraying against the tank walls" since it would be underwater. You should hear the anti-siphon valve "buzzing" under the vanity, but often from outside, you can't hear or can barely hear that valve.

If it was working previously, then it should still be working. Dump the tank, let it drain completely, then turn on the flush system and watch the sewer hose to see if anything is flowing. You can, if you watch closely and don't walk away, close the black tank valve for a few minutes, then open it and see if you get a "gush of water" as you open the valve.

But, to answer your question, "Maybe the line is kinked". Probably not, since it's rigid PEX tubing and if it has been working in the past, on a 2013 trailer, there's almost no chance that the PEX suddenly kinked.

Thanks for your reply, John. The black tank valve was open during the attempted flush and no water came out. I need to check that antisiphon valve maybe that’s the culprit. -Robert

Jbro · 05-30-2022, 07:43 AM

Quote:

Originally Posted by lonerider98

You have two gray water and two black tanks. the valves in the front compartment controls the first black tank and the bathroom gray tanks. There is a pull valve behind the tires for the 1/2 black tank. Now there is suppose to be a gray tank valve just in front of the tires. But mine is hidden in between the tires not mounted where it's suppose to be. So look for it between the tires. to shut it off.

Found it right between the tires just as you mentioned, and it was in the open position. Very happy that it wasn't a faulty valve after all!

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