Replacing the Soft Hose in a 315RLTS

[howson]

...cont from post 30...

Once I got under the sink all configured and put together I went under the trailer and cut out the soft hose. I took out a small section of pex, too, so the new junctions were in a place easy to use the compression tool.



This is what I cut out.


Lining up and cutting the new hose was surprisingly easy. The Sharkbite did bend quite easily--I didn't need any elbows or supports.



The last step was to install insulating sleeves over the lines, tape up the hole from underneath (first picture below) and add "Great Stuff" foam into the hole from the top (inside the island).




Need one more post for all the pics! Continued on next post...

[howson]

...last continuation post in a series of three...

Then tape was added on top over the foam (to keep small items from falling into this area), the "L" was reinstalled, and the leak detector was placed where it (hopefully) will do it's job and detect a leak should there be one.






Tomorrow it's the Nautilus panel's turn. Should be interesting.

Any questions or comments, fire away.

Howard

P.S. All the pex compression fittings were checked with a "go/no-go" gauge. They all looked good to me.

[howson]

One more item to document before I forget.

Every connection--all of them--without exception--had water in them. I got soaked numerous times. I was amazed at how much water (as Rob has documented in the past) is retained in the lines. Opening the low point drains does *not* eliminate all the water in the camper. I now highly doubt blowing air through the lines is effective, too. Put me firmly in the "run anti-freeze through all of the lines and plumbing systems in the RV until you see pink" camp for winterization. That includes the black tank flush system.

In addition, I'm now going to sanitize the entire system upon arrival at home, and flush it out as part of my pre-departure routine.

[howson]

BLACK TANK FLUSH (Part 2 - Complete!)

I didn't plan on doing this today, but one thing led to another and now it's done.

If you have a Nautilus panel, you know the black tank flush connection is on the bottom right of the panel. The Nautilus panel in a 315RLTS is in the front pass-thru on the street side. The black tank is approximately in the middle of the trailer, so quite a distance from the black tank connection on the Nautilus.



If you've read through this thread, you'll know from steve&renee's question and my subsequent answer (see post 23) that if that black flush connection requires replacement it will be a tough task. From that conversation sprung the idea to move the black tank flush connection.

The first thing I did was cut off the white tabs on the back of the Nautilus panel that retained the connector and extracted it intact. (I'm going to mount a pressure gauge in the now empty spot on the Nautilus, mimicking what Cate&Rob has done on his panel).

Using a 1/8" x 2" x 3' piece of flat aluminum I fashioned a mount that fits perfectly (~11.5" long) with one side resting on top of the trailer frame and the other on the top of the inside of the skirt. Then I bent a shorter second piece from the same piece of aluminum and bent it at 90 degrees. A hole was made in this second piece (prior to bending, actually) for the black flush connector. The two pieces are joined together with self-tapping screws which were then cut off flush.

The black flush is held to the aluminum with a 7/8" retaining ring. Pure dumb luck on my part that it all worked so perfectly. (I had the aluminum in my pile of "stuff" leftover from other projects.)



The aluminum was sanded, painted, and the black flush connection mounted just forward of the sewer connector after much consideration with self-tapping screws. Special consideration was made for the gas line, as I installed a clamp as a spacer to ensure there was no chaffing.

As previously noted in this thread, the black flush line goes up behind the shower (to the vacuum breaker) and then back down to the black tank. Where the flush connector is now, water has to travel forward just a short distance, then up into the vacuum breaker (that was left as originally designed and installed) and then down into the tank. (The latter parts are OEM.)

I tested the new setup and it works as expected. The best part is that when the water drains out of the black flush line (as it is supposed to do after a flush) the clean water drains on the ground instead of inside and on top of the drip panel (or whatever it is called) in the pass-thru.

Anticipating the question, I'm not too concerned about the connector getting damaged due to debris. Where It is mounted, it's aft of two large storage containers (I added them) so it is semi-protected. The likelihood is slim--I hope--that it will be damaged. If something does happen, I'm not concerned because this is a non-essential system that will be very easy to repair.

Here's what it looks like:






Any questions...fire away.

-Howard

P.S. Using a pex connector on the black hose...yes, I know that is wrong, Rob. I'm not too concerned with that connection on this system. I used the parts I had on hand!

[howson]

Fresh Water Tank Area (Sub-Project #3: Dump Handle Extension, Dump Extension, Move 2ea Low Point Drains, Install Valve on Overflow) 60% Complete

Moved the hot and cold water low point drains from under the trailer to just inside the skirt so if I want to release the water I don't have to crawl under the trailer. (There's some irony that I spent an entire day crawling under the trailer...to avoid crawling under the trailer.)

I also installed the dump handle extension. That work is documented here: https://gdrvowners.com/forum/operati...0006#post20006

For the low point drain move, there is one caution for those that are considering duplicating what I've done: if you intend on camping in very cold weather there more line exposed than before to the environment. Adding insulation on top of the lines would be easy, but the aluminum supports will transfer the cold to the bottom of the lines rapidly and will pose a challenge to keep them from freezing. (I intentionally didn't account for the possibility of very cold weather as it is highly unlikely my DW and I will willingly place ourselves in that circumstance. We'll be in our home in Florida during the winter!)

The only other comment is the first hole through the frame was a bit too large. I intended on using a rubber grommet...but that didn't work as intended. The answer (as I did on the blue line) was to make the hole the same size as the pex. The blue line passes perfectly through the hole.

At this point I should extend my norm caution and reminder to the readers: I post as I work, so these mods are untested and haven't been proven over time, so duplicate anything you see at your own risk. (As always, I'll update this thread with unintended consequences should I encounter any.)

The two valves and the handle you can see here is what I moved to just inside of the skirt for easy access.





This should give you an idea of where they were (requiring I crawl under the camper to turn on the valves) and now where they are located);





Tomorrow I'll work on the dump extension and the overflow tube valve installation.

As always, questions, constructive critiques, and comments are welcome.

Howard

[howson]

Cate&Rob (or whomever),

The Nautilus panel has a few lines that are white soft hose. Is it necessary (or a good idea) to replace with white pex or can I get away with using blue? (I'm focused on color, not "soft" vs "pex".)

What does the white signify--anything?

[Cate&Rob]

howson
Hi Howard

The color coding of the water lines is just for us humans . . . the water does not care . When Pex came out, it was all white . . . then they went to red/blue to keep the hot/cold runs easy to sort out at the other end. Grand Design has traditionally used black soft hose for tank flush, but I did notice at the last factory visits that they sometimes use blue Pex pipe for parts of the flush line run. I don't know what white hose indicates to the assembly process.

To answer your question . . . no reason that you could not use blue Pex . . . unless a different color helps to indicate what is going where.

Good idea, bringing the low point drains out to the edge, BTW!

Rob

[howson]

Fresh Water Tank Area (Sub-Project #3: Dump Handle Extension, Dump Extension, Move 2ea Low Point Drains, Install Valve on Overflow) Done!

Finished the last item in this area--a shutoff valve for the overflow on the water tank. The valve is conspicuously different on purpose. Having this valve off (not allowing air to enter or exit) while pumping water into or out of the tank will lead to a very bad result. The only time I'll have this valve closed is the rare occasion I'm carrying a large amount of water (to keep it from siphoning out of the tank). It will also come in handy when I overfill the tank and the water starts siphoning--I can easily just close the valve, stopping the process.

If you've read this thread nothing in the pictures below is going to surprise you--similar installation process. Only change was the pex is 3/4", so making the holes was "fun" (I didn't have a bit large enough, so ended up using the dremel to remove enough material to allow the pipe to slide through the hole).







Howard

P.S. The old drain lines are visible in these pictures. They will get cut out when I tackle the soft hoses to the bathroom and hot water heater. (Soon!)

[ncitro]

howson

Howard, let me know how this goes. I did something similar and find that when I fill the tank completely and close the valve the pipe causes some kind of vacuum lock. What I think is happening is the pipe has enough water in it to prevent air from coming in during use, but not enough for it to drain out (even with pitch). The pump is not strong enough/the tank is weak enough such that it is easier to collapse the tank than to pull the water out of the pipe and let air in. I have to actually take my air compressor over and blow air in until I hear the tank start to expand again and release the vacuum. As such when I pull my coroplast I’ll be in search of another method. I bought the one way sprinkler valve mentioned on the other site that I was going to try.

[howson]

howson

Howard, let me know how this goes. I did something similar and find that when I fill the tank completely and close the valve the pipe causes some kind of vacuum lock. What I think is happening is the pipe has enough water in it to prevent air from coming in during use, but not enough for it to drain out (even with pitch). The pump is not strong enough/the tank is weak enough such that it is easier to collapse the tank than to pull the water out of the pipe and let air in. I have to actually take my air compressor over and blow air in until I hear the tank start to expand again and release the vacuum. As such when I pull my coroplast I’ll be in search of another method. I bought the one way sprinkler valve mentioned on the other site that I was going to try.

Interesting. Once I've got everything back together I'll do some testing. Thanks for the note.

[Cate&Rob]

howson

Howard, let me know how this goes. I did something similar and find that when I fill the tank completely and close the valve the pipe causes some kind of vacuum lock. What I think is happening is the pipe has enough water in it to prevent air from coming in during use, but not enough for it to drain out (even with pitch). The pump is not strong enough/the tank is weak enough such that it is easier to collapse the tank than to pull the water out of the pipe and let air in. I have to actually take my air compressor over and blow air in until I hear the tank start to expand again and release the vacuum. As such when I pull my coroplast I’ll be in search of another method. I bought the one way sprinkler valve mentioned on the other site that I was going to try.

howson

Hi Howard (& Neil)

If you get the vacuum lock that Neil describes, after opening the vent line, crack open the tank drain briefly. This should be more than enough outflow volume to pull the water out of the overflow/vent line.

Rob

[ncitro]

howson

Hi Howard (& Neil)

If you get the vacuum lock that Neil describes, after opening the vent line, crack open the tank drain briefly. This should be more than enough outflow volume to pull the water out of the overflow/vent line.

Rob

That’sa good point. Given the choice I’d prefer to not have to waste some water, but if in being honest the real problem is I forget to open the valve lol. Looking to automate it either with the one way valve or the solenoid we discussed.

[steve&renee]

... the real problem is I forget to open the valve lol...

I was going to ping howson. I installed my shutoff last year, and I still forget to open the damn thing -- most of the time it seems. It takes a while to get this new item ingrained in my setup routine.

What I can't understand is even when the valve is closed, my pump seems to operate fine. Even to take a shower. The only thing that makes sense to me is that my tank *must* be redundantly vented. If not, the physics just don't add up.

-Steve

[ncitro]

I was going to ping howson. I installed my shutoff last year, and I still forget to open the damn thing -- most of the time it seems. It takes a while to get this new item ingrained in my setup routine.

What I can't understand is even when the valve is closed, my pump seems to operate fine. Even to take a shower. The only thing that makes sense to me is that my tank *must* be redundantly vented. If not, the physics just don't add up.

-Steve

I know mine operates “fine” but it is just collapsing the tank. I can tell because it continues to read full and never drops lol. Once I open the vent you can hear the tank button and let air in and it reads normal again.

One problem is we use to bathroom in the RV when we stop for fuel or at rest areas and forget to open it for stops like that. Plus I can never remember to open it when we setup.

[howson]

ncitro and steve&renee ,
That's why on aircraft all the "stuff" crew chiefs have to remember to remove (or install) has one of these:



Both switches for the pump will likely have a piece of velcro attached above the frame of the switch to allow a VENT sign to attach. When the vent is open the sign will be reversed so the switch is available.

I don't trust myself to remember.

Engineering an automated process is a much better solution. Get busy and figure one out that I can steal...um...I mean copy.