Sewer plumbing questions from a noob.

[BigTex]

Ok, so I am brand new and I am sure this info is found elsewhere, but I couldn't find it.

Is standard 3" dump lines just 3" abs? As in will standard abs fittings fit and cement to the RV's sewer lines? See, I have a blocked black dump line *somewhere*, and to add insult to injury, the push rod bent when I tried to close it back, so that's got to get fixed. I tried filling the hose with fluid and lifting it to put back pressure on the blockage, but it didn't work for me. I can't do any of the easy fixes that require you to drive the rig around because I can't close the valve. I haven't dropped the underbelly panels yet, but will be later today after I get fasteners to resecure them to figure out the best way to clear the blockage.

Maybe a snake will work, but IDK because the grey joins this dump line at some point and I don't know if I can route a snake up through it or if it will just try to go to the grey.

The other option I am looking at is trying to reverse flush. I can't find a reverse flush valve locally and all the online vendors are slower than I would like them to be. I was thinking about building my own reverse flush setup out of abs, cutting and gluing.

Any info or pro tips are appriciated. Anything from the best way to get these rivets off or secure the panel back after removal all the way to any info on my specific rig. I have a voltage 3990, 2015.

[BigTex]

Well a snake doesn't work. The black line turns at a 90 while the galley water goes straight, so the snake just goes into the grey line at that point. I have a reverse flush attachment showing up tomorrow.

Has anyone ever attempted to back flush a blockage with compressed air? The tank is pretty full. I'd hate to accidentally over fill.

[franktafl]

Did you think to put water in the tank before you started using it? Also, RV toilet paper doesn’t always dissolve so don’t I use lots of it. Make believe you are in Europe and throw as little into the toilet as possible and place a trash can near the toilet.

I replaced my manual valves with electric ones, expensive but it’s the way to go.

[Thom]

Sounds like you have one of two things happening.

1. Your dump valve push rod could have disconnected from the knife blade prior to it bending. In this case, the valve isn't actually opening and will need to be replaced, which you should already be planning to do since it is bent.

2. You could have a large dreaded brown pyramid built up in your tank. As Frank mentioned, lack of water in the tank prior to use is the prime cause of this (although it can happen from not emptying the tank prior to long term storage as the water can evaporated, leaving only solids in tank). The solution for this is to take a water hose with a high pressure nozzle on it into the bathroom and stick it down your toilet into your blac tank and try to bust up the pyramid. Most toilets are directly above black tanks so it should be a straight shot down. Tape the hose to a rod or stick to give it some rigidity which will allow you some control over directing the nozzle.
Usually with a brown pyramid, you would get a trickle of water out of drain when opened, which leads me to believe that you have a valve problem.

[franktafl]

PS: I learned about the pyramid the hard way!

[BigTex]

Ok, last night I did some destroying in the name of diagnostics. I broke the coating portion of the valve so that I could see if the valve was opening. It's open. The cable length is probably just corroded. I can look down from the toilet and see plenty of fluid, and before we used it the first time i put 4 flushes down the toilet. So, it's almost certainly plugged up at the bulkhead from black tank to drain line. My reverse flush adapter should be in today, so hopefully I'll have an empty tank tonight. 50 bucks says the previous owner used nonrv toilet paper. If the reverse flush doesn't work, IDK how effective the sprayer down from the toilet side will be. The tank drains on the opposite end of the tank from the toilet.

So, I'd decided to get away from cables. Has any one used the baker autodrain? The ability to change the valve and reuse the same actuator seems like a good option to me.

[franktafl]

I would say, go to RECPRO.COM and find a replacement for the tank. That will tell you where the tank drain is (center or side) and you should be able to snake that from the inside with taking the toilet off. Like Thom mentioned, it's a straight down drop from the toilet into the tank (for most anyway). I would say FOUR flushes are NOT enough depending on the size of your tank. I put ten gallons of water in my tank after I flush the tank. I use one of those orbit water flow gauges (from Lowe's) in order to figure out how much water I'm putting in.

[BigTex]

Originally Posted by franktafl

I would say, go to RECPRO.COM and find a replacement for the tank. That will tell you where the tank drain is (center or side) and you should be able to snake that from the inside with taking the toilet off. Like Thom mentioned, it's a straight down drop from the toilet into the tank (for most anyway). I would say FOUR flushes are NOT enough depending on the size of your tank. I put ten gallons of water in my tank after I flush the tank. I use one of those orbit water flow gauges (from Lowe's) in order to figure out how much water I'm putting in.

Right on. I'll start putting more water in it after a flush. I figured 4 would be enough because the bathroom sink also empties into this black tank instead of the galley grey. Honestly I think this is a residual issue from the previous owner, though. I dumped it first chance I got because I saw it has some left in it from the previous owner, and I didn't flush it right then (I was in a rush). I should have, because I saw toilet paper that wasn't dissolved and all kinds of crap when I emptied it. I bet you it didn't empty all the way, but instead clogged right at the end and I had just assumed it was empty.

I saw the tank when I had the panels off yesterday looking at the plumbing. The drain is at one end, the toilet is at the other. If a reverse flush doesn't work, I'll take the toilet off and try to angle the snake.

Thanks for the link. That'll come in handy, I'm sure.

[BigTex]

As of this morning, the clog is gone, the valve replaced, but leaking. Idk if isn't tight enough or if I knocked one or both of the seals off track installing it, but I'm going to have to mess with it again this evening.

I'm putting in for a baker electric valve actuator today. I'll order 2 more for the greys and one more for the other black when I land in a spot with a cement pad. I'm already sick of crawling around in the mud and gravel of this site.

Seriously considering running hard conduit for wiring along the outside of the frame instead of trying to run all this through the belly.

[BigTex]

Nevermind. Can't find a barker electric valve in stock anywhere. Guess I'm stuck using a cable.....if I can even find a cable valve.

[BigTex]

Does anyone here know if a valterra valve will work between bristol flanges?

[franktafl]

I would imagine if the bolt pattern is the same they will work.

[Thom]

So, in order for us to understand and better help others, can you tell us how you finally cleared the clog?

[pctomlin]

I built this using a Rainbird sprinkler head to ensure my black tank stays clean, set for 360 degree rotation . Insert it through the toilet and let it go to town. I added a valve to the main outlet so I can backwash grey water into the black tank also.

[BigTex]

Originally Posted by Thom

So, in order for us to understand and better help others, can you tell us how you finally cleared the clog?

Sure! I used a back flush attachment like this:

https://parts.unitedrv.com/products/...BoCGV4QAvD_BwE

Basically, you close the valve on the attachment and open your dump valve allowing you to backfill the line with a water hose, pushing the clog back into the tank, giving it a second chance to behave when you open the dump line again. The clog cleared instantly once the line filled and pressured up. I back filled the tank and re emptied about 5 times to get everything out of it. That tank is downright sparkling at this point.

The real challenge was locating parts. Everyone cites the pandemic and complains that they haven't been able to get rv parts for 90+ days. I thought I was going to have to build my own back flush system out of abs until I finally found one in stock.

Even stuff that should be common shelf items have been a challenge to get. It took me days to get that back flush thing in the mail. It's taking me 5 days to get a valve with a cable on it (it's a good thing I have 2 toilets in this rig). Forget finding electric valves at this point. Just isn't happening. The last couple spots that do have them have marked them up another 50% and you can't be picky about the brand if you are going to buy one. Sorry, but I'm not in the business of overpaying for stuff.

[BigTex]

Originally Posted by Thom

So, in order for us to understand and better help others, can you tell us how you finally cleared the clog?

Sure, I used a back flush attachment like this:

https://parts.unitedrv.com/products/...BoCGV4QAvD_BwE

Basically you plug this thing onto your dump line, close your grey valve and the valve on this attachment, open your black valve and attach a garden hose. The clog cleared instantly once the line filled with water from the hose and pressured up.

The real challenge was finding this thing. I thought I was going to have to build one out of abs and cement it into the system until I finally found a supplier who had one and would expedite it to me. Everyone is citing the pandemic saying that they haven't been able to get rv parts for like 90 days. It's taking me almost 4 days to get any 3 inch dump valve with a cable. I'm really grateful to have 2 toilets on different tanks.

I gave up finding an electric valve. The 2 suppliers I have found who have any have marked them up 50% more and they aren't even the model I really wanted to buy.

[BigTex]

Originally Posted by Thom

So, in order for us to understand and better help others, can you tell us how you finally cleared the clog?

Certainly. I used a back flush attachment called the "flush king." Basically it is a 45⁰ clear attachment you connect between the dump line and the sewer hose. It has a knife valve and a checked port for a water hose. I closed the grey valve on the rv and the valve on the flush attachment leaving the the black open then turned on the hose. The line fills, and then if the clog is still intact, pressure builds in the line until it pushes it back into the tank, giving it another opportunity to behave when you dump again. Worked very well. I filled and dumped another 4 times through the back flush attachment. That tank is practically sparkling now.

The main problem was locating one. Most vendors I spoke to said they were having a really hard time getting parts citing the pandemic.

Speaking of having a hard time getting parts, I am waiting on a cabled valve. Even what should be shelf items aren't nessicarily easy to get ahold of right now. Forget electric valves for the time being. I only found 2 vendors that had them in stock in the entire country and neither where the brand I had decided to go with. They both had limited stock and wanted an additional 50% markup for what they had left. Hopefully the stock issues will work themselves out soon. I had myself all worked up and ready to install electric throughout the entire rig.

[Thom]

Thanks for the reply!

[steve weston]

who built the pyramid ?

[RetirementTime]

I love my Valterra Flush King. It has got me out of "black water" a few times. Plus with the pipe being clear I always know when the tank is completely empty and clean. It works well in combination with the pre-installed San-T-Flush. But if I had to pick just one, the Flush King would be the easy choice.