How to really empty your black tank

[Scottenj]

We have a 355MBQS Eagle Fifth wheel that we took delivery on early May 2019. We have had continuing issues with our black water tank and I finally got to the bottom of it and learned some things I have not seen anyone else talk about.

Our first trip was for a long weekend at a campground with full hookups, at the end of the trip I dumped the black tanks and the 1/3 third full light stayed on. Our next trip was 6 days at a music festival, the 2/3 light came on the first day and within a couple more days the full light came on. I had the porta potty guys drain our tank, it did not seem like that much effluent came out and the 2/3 light stayed on. Our next trip was ten days at a campground without hookups. Once again, the tank seemed to fill quickly, and I had to use my tote tank to go to the dump station frequently. At the end of the trip I spent a long time at the dump station flushing and emptying the tank, but the 1/3 full light stayed on. Now I should note here that I do know the lights are often not that accurate but with a bunch of kids using the toilet I did not want to push my luck.

When I got back home, I decided I had to get to the bottom of this. I filled the tank until it backed up into the toilet multiple times adding different treatments each time, letting it sit for days and then dumping. At first the 2/3 light was staying on. I tried adding bags of ice and going for a long drive, I top and bottom filled the tank, tried the spray bars, etc. The bottom fill seemed to help, and I got back to only the 1/3 light being on. I tried putting an endoscope camera I bought on Amazon down the toilet and I saw some liquid in the bottom of the tank but when I pushed the camera down into the liquid it immediately hit the tank bottom so the liquid appeared to be just a film. The camera was however limited to just seeing right under the pipe that runs down from the toilet.

I then took a Save a Drop water meter and filled the tank until it backed up into the toilet and it only took 37-gallons. This made me think that If the tank was empty it might be the wrong size. I had a black tank cleaning expert tell me it is not uncommon for RV manufacturers to put in the wrong size tank, but first I wanted to test the meter, so I filled a 5-gallon bucket and it read five gallons, I filled my 50-gallon gray tank and 35-gallon gray tanks and got roughly 50 and 35-gallons. Top filling you are going to be filling piping that run down to the tanks so you should read slightly high and in both cases it did.

I contacted the dealer and said I thought I had the wrong size tank, they contacted Jayco and I had a phone conversation with a high level Jayco customer service guy. I explained what I had done and he agreed it sounded like I had the wrong size tank and that Jayco would pay to replace it. Ironically the first replacement tank Jayco sent was 35-gallons but we finally got a 50-gallon tank. The techs at the dealer opened the bottom of my camper, in my camper the 50-gallon gray tank for the bathroom and the 50-gallon black toilet tank sit right next to each other under the basement. The tanks are around 6 feet long, 2-1/2 feet wide and about 6” high. The two tanks were the same size and even the same part number as was the new 50-gallon tank. When the tech and I looked at the black tank the bottom was bulging down in the middle. There are basically two steel bars that run across the unit between the I frame and the bars are about a quarter of the tank length from each end leaving about half the tank length unsupported. When I pushed up on the bulge it was clear to both of us that there was liquid in the tank.

Now at the point I was embarrassed that I got this wrong about the tank size and I paid the dealer for the time they put in.

The tanks drain at the back and the dealer owner suggested I try raising the front of the camper when I go to dump. I took the camper home, put about 4-gallons of water in a 5-gallon bucket and added a scoop of Happy Camper (by the way, I was surprised that a lot of the Happy Camper actually stuck together into a very hard kind of rock in the bottom of the bucket), I dumped it down the toilet and let it sit overnight. The next day I put the front all the way up (I was surprised how far up it will really go), I hooked up a clear elbow and a hose to my 30-gallon tote tank. I opened the valve and about 15-gallons of effluent ran out into the tote tank. I then got underneath and pushed up in the middle of the tank and another 5-gallons or so ran out. I also did this to my 50-gallon gray tank and got some liquid out of it as well. Once I leveled the camper the lights were all out for my black tank! My new dump procedure will be to raise the front of the camper and push up on the tanks when I want them to fully empty and I should now have about 20-gallons of additional black water capacity as I have apparently been driving around with 15 to 20-gallons of black water in the tank since the first time I used the camper.

The other interesting part to all this for me was weight related. I own two utility trailers and I learned a long time ago that it is really easy to put thousands of pounds of stuff into a trailer. With my travel trailer I had previously worried about overloading it and the closet CAT scale is pretty far away, plus we don’t typically finish putting food and clothes into the camper until the day we leave and it isn’t convenient to go to the scale. I decided with my Fifth Wheel that since I knew the factory weight I would weigh everything I put in it and build a big spreadsheet and when I was going somewhere I would just fill in how many of each item I was taking and know I am OK (yes I am OCD). So, I did this but when I went to the CAT scale to check my numbers the camper was almost 400 pounds too heavy. With the black tank and 50-gallon gray holding onto maybe as much as 25-gallons, plus the water heater is 6-gallons and I typically pump out the fresh tank at the end of trips as opposed to opening the low point drain, that turned out to be another 5-gallons. In total around 36-gallons of retained fluids is 300-pounds, so much closer. I generally run empty tanks because everywhere I go has water available so now I can reduce my weight by 300-pounds and have more capacity for stuff or camper modifications (I have done a lot of modifications and am working on a write up of what worked well and what didn't).

So there you go, tilt up the front and "burp" the tank. The black tank on mine is on the door side and the gray tank is on the dump side. Underneath you can see where the cross bars bolt to the I beams so push up in between them.

[RAurand]

Very interesting!

[Racinforthefinish]

I would have had the dealer put something else under the tank so it would drain better. This would be an easy fix. There is no way I would go under and push up on something I .had to pay for.

[Mopar_Earl]

Originally Posted by Racinforthefinish

I would have had the dealer put something else under the tank so it would drain better. This would be an easy fix. There is no way I would go under and push up on something I .had to pay for.

I agree. I'd of had the dealer fix under warranty. Either replace the bulging tanks or support the bulging areas if the new tanks would bulge.

And to crawl under there while at the poop dump with all the spills and leaks. Nasty! Think I'd rather go in a Walmart. Lol


Earl

[Marcm157]

Couldn't tell you are OCD from your post! BTW I am CDO. It's just like OCD but the letters are in the correct order...

[Scottenj]

Originally Posted by Mopar_Earl

I agree. I'd of had the dealer fix under warranty. Either replace the bulging tanks or support the bulging areas if the new tanks would bulge.

And to crawl under there while at the poop dump with all the spills and leaks. Nasty! Think I'd rather go in a Walmart. Lol


Earl

The warranty status of my unit is kind of a gray area.

I have thought about bracing the tank, I was also running a wire tonight and I had the back wall of the basement open. I noticed I can look down and see the black tank outlet and it looks like it slopes up to the sewer line. I am heading out for two weeks next Wednesday but when I get back I am going to open up the bottom and make some decisions.

In the mean time I have big piece of cardboard to put down if I slide underneath and it is the side away from the waste outlet. I definitely won’t be rolling around in anyone’s effluent.

I also installed a new inverter tonight only to find out it is defective brand new right out of the box. The literature says neutral and ground are bonded together inside the inverter per the electrical code but hot to neutral is 117 volts, hot to ground is 58 volts and neutral to ground is 58 volts.

[dkegel]

Interesting story but I don't quite understand how I'd raise the front of my fifth wheel when at the dump station. It would be hooked up to my truck at that point. What am I missing?

Dave

[Mopar_Earl]

That's always my luck too, having bad out of the box stuff. Sometimes months after I bought it.

The poo dumps I've been to have bits of TP everywhere on both sides and middle. Like they dumped without a hose and not even near the dump port. Or their tank exploded. People can be so dirty.

Keep us posted on what you find and if you do anything about it. Makes me wonder if my tank sags or not. I know I have to fill it completely and dump 3 times in a row to get it to stop flowing out solids. Just using the flusher with the valve open doesn't cut it. So we do that till it runs clear with no debris. Then do the fill completely and dump it 3 times or more if needed. Which takes a lot of time and the dump stations always seem to have the worse water flow. Guess I need to check for sagging on my black tank.


Earl

[Scottenj]

Originally Posted by dkegel

Interesting story but I don't quite understand how I'd raise the front of my fifth wheel when at the dump station. It would be hooked up to my truck at that point. What am I missing?

Dave

You have to unhook to do it.

[Scottenj]

Originally Posted by Mopar_Earl

That's always my luck too, having bad out of the box stuff. Sometimes months after I bought it.

The poo dumps I've been to have bits of TP everywhere on both sides and middle. Like they dumped without a hose and not even near the dump port. Or their tank exploded. People can be so dirty.

Keep us posted on what you find and if you do anything about it. Makes me wonder if my tank sags or not. I know I have to fill it completely and dump 3 times in a row to get it to stop flowing out solids. Just using the flusher with the valve open doesn't cut it. So we do that till it runs clear with no debris. Then do the fill completely and dump it 3 times or more if needed. Which takes a lot of time and the dump stations always seem to have the worse water flow. Guess I need to check for sagging on my black tank.


Earl

Is your 1/3 full light always on? Everyone I know with a fifth wheel says their 1/3 light never goes out, that is what I found interesting was that after doing this it finally went out. I had been thinking the sensor was fouled but now it seems it was working correctly and the tank was really 1/3 full.

[Mopar_Earl]

Originally Posted by Scottenj

Is your 1/3 full light always on? Everyone I know with a fifth wheel says their 1/3 light never goes out, that is what I found interesting was that after doing this it finally went out. I had been thinking the sensor was fouled but now it seems it was working correctly and the tank was really 1/3 full.

No, my sensors work great. But I use treatment and flush the hell out of it. My sensors are mounted on the outlet side of the tank beside the outlet, not on the side. So any sagging wouldn't be near the sensors.


Earl

[dkegel]

Originally Posted by Scottenj

You have to unhook to do it.

That would not be practical for us, if for no other reason than there's almost always someone waiting in line.

Dave

[Cavie]

Make the dealer fix it. No reason to raise the front or push up on the tank!!!!

[Trapper2020]

My grey tank held water because of the sag in the tank. To fix I got some pieces of wood and slid them in between the metal bands and the bottom of the tank. Then ran a short screw through the metal band into the wood to keep it in place. Easy fix. No more bad smells from grey tank. You may look at doing the same thing. Surely a lot easier than lifting rig and pressing up on tanks to drain. Take care

Enjoy the journey

[Scottenj]

Originally Posted by Cavie

Make the dealer fix it. No reason to raise the front or push up on the tank!!!!

Not entirely clear at this moment what I want them to fix. Yes the tank bulges but from what I have heard that is common on fifth wheels. The other thing I found two nights ago is it looks like the tank outlet is sloped up to get to the sewer line, but I need to open up the bottom to really look at it. I'm about to head out for two weeks and will open it up when I get back.

There is also some issues around my warranty and what I can get them to do at this point, but that is a long story.

This has been a long journey and I was pretty excited when I finally found something that worked, the excitement is wearing off as I consider the piratical reality.

[Scottenj]

Originally Posted by Trapper2020

My grey tank held water because of the sag in the tank. To fix I got some pieces of wood and slid them in between the metal bands and the bottom of the tank. Then ran a short screw through the metal band into the wood to keep it in place. Easy fix. No more bad smells from grey tank. You may look at doing the same thing. Surely a lot easier than lifting rig and pressing up on tanks to drain. Take care

Enjoy the journey

Thanks, I have been thinking of doing something like that or putting in a brace. I also found the other night that the outlet line looks like it slopes up to the sewer line and that may be another contributing factor. I am heading out for two weeks in a few days and will open up the bottom of the rig when I get back and decide what to do.

[triplebvalp]

Scottenj, although I know longer have our Jayco Eagle HT 27.5RKDS, we now have a Montana High Country. In order to completely drain the black tank and the bathroom grey tank, I have to elevate the front of the FW.

It's interesting to note that the Montana folks are aware of this "feature". There is a video of a walk-thru of the Montana plant. The guy doing the walk-thru actually tells the customers that to completely empty the tank(s), you gotta raise the front. He goes on to say that they know that this might be impossible while at a dump station since you gotta unhook.

Fortunately, I can do a final dump my tank(s) at my home.

[Scottenj]

Originally Posted by triplebvalp

Scottenj, although I know longer have our Jayco Eagle HT 27.5RKDS, we now have a Montana High Country. In order to completely drain the black tank and the bathroom grey tank, I have to elevate the front of the FW.

It's interesting to note that the Montana folks are aware of this "feature". There is a video of a walk-thru of the Montana plant. The guy doing the walk-thru actually tells the customers that to completely empty the tank(s), you gotta raise the front. He goes on to say that they know that this might be impossible while at a dump station since you gotta unhook.

Fortunately, I can do a final dump my tank(s) at my home.

Thanks, I think this kind of issue is a lot more common than people want to admit. I was shocked when I saw how shallow my fifty gallon tanks are, they squeeze them in under the basement in a space that isn’t very tall. People I know with fifth wheels joke they come with the one-third full light on from the factory and seem to think it is a sensor issue, I am thinking it is really because the last 15 To 20 gallons never drain.

[Pamtha]

@triplebvalp - we traded in our Montana HC for our Eagle, and you just gave me flashbacks. Dumping that black tank was always traumatic - it was like it was plumbed level and never came out more than a gentle flow, even when just water for flushing. I never thought of raising it -- but I don't miss it and we are loving our new Eagle.

[Mopar_Earl]

Raising the unit would only help if the outlet is facing the rear. If to the side or front, raising wouldn't help. Would depend on the tanks outlet position. My Eagle the black and gray point to the rear. The galley gray points to the road side.


Earl