2020Imagine 2500RL Black tank won’t completely empty

[2020Imagine]

My black tank will not completely empty when the RV is level. I have to raise the passenger side of the RV up two inches above level for the tank to completely empty. The issue became evident when I removed the exterior cap to attach my sewer hose and raw sewage came out. Because the tank didn’t completely empty the last time I emptied it something kept the valve from completely closing and let stuff pass through when we were traveling.
has anyone else had this problem? Joe

[Cate&Rob]

2020Imagine
Hi Joe,

What you describe is not an unusual situation. The tanks are shallow and flat with drain connections in the end that do not allow the last half inch of contents to drain even if everything is perfectly aligned and level. Travelling with a gate valve that does not seal completely means that tank slosh will put tank contents into the drain pipe. Many of us put a twist on gate valve on the drain hose connection. This allows you to take off the cap and get the hose connected before opening this gate to anything that might be behind it. Solving why your black tank gate valve is not closing completely is the issue to be worked on.

Rob

[Country Campers]

2020Imagine

I agree with Rob above. We have had this issue with all of our past RV's of all brands. The twist on gate valve is a great investment. We also add about 5 gallons or so of water after dumping to keep the tank from drying out and while traveling the water sloshing around helps with keeping it clean as well. This may also remove the debris that may be in the black tank valve.

Brian

[2020Imagine]

Thanks guys for your response. I just purchased the gate valve to avoid having raw sewage from running out when I remove the cap. I now know I’m not alone with issue. It’s great to have this forum to share issues and get actual owner information.
Joe

[MAW7228]

Just read with interest this post on leakage in the drain pipe. I have a similar issue with my 2020 337RLS fifth wheel. Can you recommend a specific manufacturer for the twist on gate valve?

[Country Campers]

Just read with interest this post on leakage in the drain pipe. I have a similar issue with my 2020 337RLS fifth wheel. Can you recommend a specific manufacturer for the twist on gate valve?

I purchased the Valterra model , these are available at camping world , amazon , and maybe walmart , and your local camper dealer may have them as well. The 3" valve is what you will want.

Brian

[MAW7228]

Thanks Brian. Did some further browsing and found the Valterra T58 online. Plan to pick one up and install it. Have you had any issues with it coming loose from the drain pipe?

[ckreef]

Thanks Brian. Did some further browsing and found the Valterra T58 online. Plan to pick one up and install it. Have you had any issues with it coming loose from the drain pipe?

I installed one of those. I didn't have any problems with it coming loose but I didn't want any problems either so I ran a short stainless screw into the pipe, on the top side, just behind one of the "hooks". As a side benefit somebody can't just walk up and take it without a screwdriver in hand.

[MAW7228]

Thanks Charles. With a little browsing I found several different options for securing the gate valve to the drain pipe (hose clamp, cotter pins, silicone, ABS cement). Once I pick up the valve I'll see which one works best for my unit. The stainless steel screw you used might be the easiest and least expensive to implement.

[Country Campers]

Thanks Brian. Did some further browsing and found the Valterra T58 online. Plan to pick one up and install it. Have you had any issues with it coming loose from the drain pipe?

I do not have anything securing the valve to the pipe. I do have the valve handle pointed to the rear of the camper , no problems for 3 years.

Brian

[howson]

Thanks Charles. With a little browsing I found several different options for securing the gate valve to the drain pipe (hose clamp, cotter pins, silicone, ABS cement). Once I pick up the valve I'll see which one works best for my unit. The stainless steel screw you used might be the easiest and least expensive to implement.

I installed a screw similar to ckreef to prevent the valve from departing the camper while towing. Unfortunately I managed to drive the screw right through where the gasket resides. It didn't cause an issue for over a year until suddenly where the screw was a leak developed. (Probably because a tank upstream was bypassing and now fluid was sitting behind the Valterra.)

I replaced the Valterra and fixed the gasket on the trailer side and have not secured the valve in any manner this second time around. No issues to date. Many other owners have reported similar results (no extra security required).

And if anyone is that desperate that they'd steal a "used" Valterra valve...wow. I'd guess they'll steal the sewer hoses and all the attachments, too, if they are taking the Valterra. While they are at it, the power cord will go, too. Never heard of that happening, but it is 2020...

[pribons]

Just got on the forum and I am having the same issue on my 31mb with the valve leaking and I have a valve on the outside to prevent this. I wanted to backflush the grey tanks, but with the black tank valve leaking I didn't want to contaminate the grey tanks. I was thinking about changing the valve, but I didn't know if there was some sort of sealant required. Did I just read that it is not required?

[ThePowells]

pribons Welcome to the Family and the forum! I'm sure that others will chime in. When you say "back flush" I understand that you are flowing water from the outlet back into the tank? IMHO, I don't see the contamination risk, unless you back flow enough to force water back up out of the drains. I, as well as many others will "equalize" the black and gray tanks when the gray does get full. I just open the gray valve and let it set for a few seconds then open the black for maybe 6-7 seconds and close the black and then the gray. With the amount of soap products going thru the gray tank, I don't think a little blak water will hurt.

[howson]

Just got on the forum and I am having the same issue on my 31mb with the valve leaking and I have a valve on the outside to prevent this. I wanted to backflush the grey tanks, but with the black tank valve leaking I didn't want to contaminate the grey tanks. I was thinking about changing the valve, but I didn't know if there was some sort of sealant required. Did I just read that it is not required?

First -- welcome -- and please check out the Welcome Letter to New Members here: https://gdrvowners.com/forum/main-fo...to-new-members

The thread is long (sorry!) but it does document what I learned when I first tackled a similar problem: https://gdrvowners.com/forum/operati...valves-315rlts May not be 100% applicable, but surely there's something that will help.

Regarding "contaminating" the grays...it is unlikely IMO that mixing the two ("It's all pipes!" - George Costanza) will cause any issues. If the black tank was full there could be <ahem> "stuff" larger than 1.5" which, if forced back up the drain pipes, could clog the smaller gray tank drains.


A funny clip from Seinfeld on the topic (where I got the quote from):

[Lonestar]

One of the best Seinfeld episodes of all times!

I know this issue of black water leakage has been discussed over and over, but I found it was not my valve leaking. After flushing my black tank I filled it about half full of fresh water, closed the valve, and left the cap off for a week. No leakage, showing it was not the valve.

With my trailer I feel there is a low point in the 3" discharge pipe after it comes out of the tank. There is a little waste water captured there, and in traveling down the road it moves towards the capped discharge end of the pipe. There it stays until I open the cap and it pours out on my shoes.

All solved with the Valterra valve. And also, a small screw in the 3" pipe, not the Valterra valve, placed as a "stop" to prevent turning of the valve, works great.