Gray Dump Valve Mod (Added to Kitchen & Bathroom Drain Lines - 315RLTS )

[howson]

This is a new modification and is NOT time-tested, so duplicate at your own risk. If there are unanticipated complications encountered in the future there will be subsequent posts documenting the issue(s).

Before I get into the details, a quick acknowledgement of my fellow moderator Cate&Rob as the idea to use couplers was "stolen" from one of his many plumbing-related posts.

The first question readers usually have is, Why this mod?. The answer: I was tired of fighting the valves that are glued to the tanks which are buried up under the coroplast. I was also tired of the rusting cables. The OEM setup has failed (on my camper) three times now, so it was time to try something new.

I'd seen valves on a travel trailer below the coroplast with simple pull valves and thought, "I wonder if if that will work on my 315RLTS?" So I tried it. The rest of this post (and likely subsequent posts) will detail how it was accomplished. At the end of this first post is a parts list.

PART 1 of 2
A quick orientation: the 315RLTS has three gray tanks and one black tank. Front gray is for the washer, next gray (going rearwards) is for the bathroom, then the black tank, then the kitchen gray. The cable on the kitchen gray had failed which started this modification.




Here's a side view of the two lines before they were modified (ignore the tape wrapped around the 1.5" drain pipe:




Here's what it looks after the install:




Close up view of before and after



Part 2 (next post from me) will detail how I figured out how to install the valves. Also, the bathroom valve has leak-checked good for ~12 hours and the kitchen valve (which was just finished) has passed an initial leak test. (There's about 40 gallons of water that was equalized between the two tanks--no evidence of any leaks.)


Parts List
4 ea PlumbQuick P1056-150 1 1/2" x 1 1/2" Couplings https://www.lowes.com/pd/Fernco-1-1-...ing/1000075329
1 ea DWV Drain Pipe - Black ABS Custom Size and Length 1-1/2" (1.5) - 1.5" x 2' https://www.amazon.com/gp/product/B07C29H74G
1/2 pint LaSalle Bristol ABS Solvent Cement - Black https://www.etrailer.com/RV-Sewer-Ho...447530889.html
2 ea Valterra Waste Valve for RV Gray Water Tank - 1-1/2" Diameter - Hub to Hub https://www.etrailer.com/RV-Waste-Va...ra/T1001B.html
1 ea 45 degree ABS elbow* https://www.amazon.com/U5806-11-HXH-.../dp/B002714N6M

*You'll likely see in post 2 that I "cheated" and used a PVC 45 degree elbow since I neglected to order the ABS version. A quick application of black spray paint and no one will be the wiser. Uh...except for all of you.

[howson]

Part 2

Hopefully self-explanatory on the bathroom gray.



The kitchen gray was more of a challenge due to the space and 45 degree angles..



If it's not obvious, if there's a failure with one of these valves it will be easy to remove the assembly (just unscrew the couplers and remove the valve) to work on it on a bench. Should be very easy to change the Valterra seals and knife valve as required.

Oh--and for those who may be wondering--I took out the kitchen gray cable and secured the valve in the open position. I hope to never see this part of my camper again!



If there's something not clear fire away.

Howard

[Cate&Rob]

Hi Howard,

I have no doubt that the sleeves will work to secure the gate valves but make them easily removable if need be for service. I am surprised that you have had so many repeat problems with the gate valves. After I installed the grease zerk fittings, mine have been trouble free. Now that your gate valves are accessible, you might want to consider this mod. (I can get at mine because I have opening panels in the underbelly coroplast . . . for those who may not know the history to this discussion)

The only concern that I would have is that moving the gate valves below the coroplast makes them and the liquid they are holding back, much more susceptible to freezing. If you travel or use the trailer in sub-freezing temperatures, the tanks are going to have to remain completely empty (and I would worry about slosh of the last 1/2" that won't drain past the original gate valve) to keep the drain pipe leading to the new gate valve from filling, freezing and possibly splitting.

Rob

[howson]

Cate&Rob -- I'd thought about the freezing aspect, but (for me) it's very rare to be in below freezing weather (while camping). For someone like Dallas ( d2reid ) a mod like this would have to consider some form of heat tape or other mechanism to account for the potential.

[Jimmer]

I like it! Very clever! I just had my kitchen sink gray valve replaced yesterday under my 1 year warranty! Unfortunately, the mobile RV guy thought he had a replacement pull cable for the valve, but he did not. He replaced the tank valve, but that did not solve the problem, as it turns out the issue is with the cable. There has got to be a way to make a more durable cable of the tank valves.

[Jimmer]

For my kitchen gray tank dump valve that was replaced yesterday, the failure was related to the cable being exposed to the elements. So a simple solution might be to put the three pull handles inside a waterproof box, like I used as my combiner box for my rooftop solar. Should be pretty straightforward to secure the box using the nuts which secure the cables to the RV bracket.


What do you think about this?

[howson]

What do you think about this?

I've had little luck with the steel cable that is in the sleeve of the Bristol. That's actually the focal point of the failures I've experienced, not the knife valve assembly itself. Perhaps those with the Valterra version have better results? And no, the Valterra and Bristol are not interchangeable (without changing the entire assembly--which is next to impossible since one side is glued to the tank).

Extensive notes on my first battle in this thread: https://gdrvowners.com/forum/operati...valves-315rlts

[ncitro]

howson I have considered this as well. I do occasionally camp in colder temps and that has prevented me from making the change. When my unit was new the black valve failed, and since then I have replaced one grey and the black again for the same reason. I can feel my black stiffening up again, and can tell its corrosion inside the sleeve against the steel rod. I have also considered the electric valves, but in addition to their cost they recommend an orientation thats not possible with my tank location (vertical as I recall).

[Cate&Rob]

ncitro howson

On my way to figuring out that I needed to install zerk grease fittings on my gate valves, I cut a seized gate valve apart. The location of maximum binding in operation of the gate valve is where the stem that moves the gate comes out through a rubber bushing at the back of the gate cavity. There is no way to get lubrication to this location. Down the cable does not go this far. In the tank gets wiped off by the gate seals. This led to my idea of using a zerk fitting to fill this back cavity with grease. Seems to be working so far.

Rob

[ncitro]

ncitro howson

On my way to figuring out that I needed to install zerk grease fittings on my gate valves, I cut a seized gate valve apart. The location of maximum binding in operation of the gate valve is where the stem that moves the gate comes out through a rubber bushing at the back of the gate cavity. There is no way to get lubrication to this location. Down the cable does not go this far. In the tank gets wiped off by the gate seals. This led to my idea of using a zerk fitting to fill this back cavity with grease. Seems to be working so far.

Rob

Yeah I've certainly considered that as well, obviously that then requires access to the valves for greasing. How often would you say you add grease?

[Jlawles2]

Cate&Rob rob have you considered extenders for the zeros to avoid having to open the doors? https://locknlube.com/products/greas...0aAiSCEALw_wcB

[Cate&Rob]

ncitro
About twice a year, I have the underbelly doors open for whatever reason and give the gate valve zerks a pump of white grease.

Jlawles2
Extenders would certainly work for greasing the gate valve zerks, but there is so much going on under there that I built opening doors that allow me under belly access with the removal of a few screws. You can see the zerk fitting on one of the gate valves and one of the rubber sleeves on the drain manifold. I divided the drain manifold into three pieces (one for each gate valve) so that any one gate valve can be removed without disturbing anything else.

Rob

[DarnDave]

On my last fiver, an SOB unit, I had so many troubles with the cables, that on this unit before delivery I had the dealer install 12 volt Barker auto drain valves https://www.amazon.com/Barker-24130-...e%2C180&sr=1-2. This involves replacing the gate valve with one that does not have a cable, just a pull rod. The Barker unit attaches to that. Electric switch was installed in the upper region of the Nautilus compartment. I only did the black tank, because at that time I could only get my hands on one Barker unit. The valve is oriented so that the pull rod is oriented "up", thus keeping the effluent flow (hopefully) out of the blade mechanism inside the gate valve. I have the twist on valterra "good neighbor" valves on both exhaust pipes outside https://www.amazon.com/Valterra-T58-...e%2C173&sr=1-3 just in case something gets by the main valves, Keeps the ground clear of messes as long as you hook the sewer hose up first .