Its done, all 3 gate valves replaced in 2016 Imagine 2600rb !

[wudwork]

I found the original cables (now 1.5 years old) difficult to pull; in particular the galley gray was quite difficult to move.

I had a friend help me do this and it took us around 3 hours to do all 3 valves. We wasted a lot of time using small vise grips in lieu of 1/4 drive ratchet (which I forgot at home). All this was done, in pouring rain, at our seasonal campsite; nowhere near ideal conditions.

About sanitation; I took trailer to dump station and use THIS tool to get the bottom of black tank completely clean. When you open those pipes, you do not want surprises. We did have a bucket ready, and it did catch some gray water.

We found the job to replace all 3 to be very simple, but there were a few areas that a 2nd person made a big difference. One was pulling apart the flanges so the new valve can slide in between. We did NOT have to cut into any pipe, there was enough slop to get new valves in. Second was holding down the coroplast below the entrance stairs so I could pull it way from the drain pipes on other side. Getting the coroplast back into place is easy to do if you have a helper. Also, holding the old bolts and flashlight while I cut them off.

On my Imagine, the black tank is at the very back of trailer. My shower gray tank is about a foot away going towards front of trailer. Both tank exit holes face side of trailer with slide. The galley gray is a few feet away from forward axle, going towards from of trailer. Its very easy to identify location by looking underneath and observe where pipes come down thru the Coroplast. Black tank valve was 3 inch Lasalle-Bristol, with fixed 36" cable. The shower gray tank valve was 1.5 inch Lasalle Bristol with 36" cable. The galley gray tank valve was also 1.5 inch Lasalle-Bristol with 36" cable. The routing of all existing cables seemed right; bend radius was at least 1 foot.

To access black and shower gray tank, we simply picked at the expando foam (no tools, it sticks to coroplast, and frame, but breaks away in chunks). We then unscrewed all bolts behind rear wheels then twisted and manhandled the coroplast down and rolled it (as well as aluminum foil "insulation") into about 1 foot radius towards rear axle. That opened up the entire rear behind the rear axle and kept the coroplast intact. I did NOT find the wiring to be a mess. Seems they held the wires up (between tanks) by hand and shot some spray foam up to "bond" the wires to subfloor. Didn't look pretty but it worked to keep the wires from laying on Cloroplast.

BLACK tank: I bought THIS Valterra valve. We found the tank has a 4-bolt flange about 6" from tank opening that mates to gate valve. On the other side of gate valve is another 4-bolt flange. We found the Lasalle-Bristol and Valterra valves to be fully interchangable; they both mate perfectly to these "generic" flanges. One thing we did learn; the Valterra valves come in 2 main parts. One is the part where the gate blocks water, the other is the part where the cable connects to valve. We found installation to go much easier if you remove the top part of valve (see orange arrows in graphic). This is because the Valterra valve encapsulates the edge of both pipe flanges; where the Lasalle valve did not. If you don't disassemble the valve; getting the new Valterra into position is very difficult because you need to sandwich the pipe flanges in the valve yet have enough room to get the valve into position. In the below picture, reference the valve piece that surrounds the bolts the red/green arrows points to. That is the part that encapsulates the flange on either side of valve.

Shower gray tank: I bought THIS Valterra valve. Same experience as black valve. We did change the orientation of valve. Instead of valve pull cable existing towards front of trailer, it now exits towards rear so I can easily fit this to new pull handle location. I then screwed the supplied bracket to the frame next to black tank valve and mounted shower gray valve to that. Now when I dump, both the black and shower gray tank valves are adjacent; no more crawling under the slide to access the shower gray pull. (yes, I abandoned the "old" gray valve holder located under the slide).

Galley gray tank, same valve as shower gray. We only had to remove 1/2 the coroplast bolts (along front of trailer) and pull down just a section of coroplast. We did end up needing to slice the coroplast about 16 inches, along the axle. This was the ONLY cut we made to coroplast.

For all 3 valve cables, I looped them so they lined up with respective pull holder and valve. I supported them with a bunch of tie wraps so they hang and can move a bit but not lay on coroplast. I chose not to cut them to a shorter length as I felt that would result in a radius that would increase pull resistance.

I plan to use THIS TAPE to close all the holes (where we picked away the spray foam) and I will likely seal all the joints between coroplast and frame. This is as much for my subtle attempt at rodent control as well as keeping the bottom sealed for reasons I don't know.

One last, but very important thing. We found both 1.5 inch valves had flange bolts that were NOT removable. It seems when the trailer was assembled, they bolt the valves to flanges THEN glue the pipes into place. We could not get 2 bolts out (red and green arrow below) as the PVC nearby blocked them and we could not get them to clear away from flange enough to reuse with new valve (I could not slide the new valve in, there was not enough play in the pipe). We had to use a cutting tool LIKE THIS with a steel cutting blade. We also found the Valterra bolts are 2 sizes. The longer size bolt is 1/4 inch too short. At each of the 1.5 inch valves (green and red arrows), we could not get the new bolts to come thru the nuts all the way. I will need to get back under and replace those new bolts (on each valve) with longer.

The attached diagram attempts to show the areas to remove coroplast bolts. The more you remove the longer it takes to put back.

Would I do this again ? yes, in a heartbeat. Getting underneath is invaluable. The valves pull MUCH smoother now and in the event the cables get difficult to pull, these are now Valterra thus cable replacement is an option. In addition, I learned all about tank sensor locations (another forum post to follow) and where things are located. I also need to put a label on the tank pull handles. All 3 are now black and not obvious (to someone else) what handle opens what. Maybe the plastic handles can be painted ? They are held in by a very small pin. The Lasalle handles have a set screw that goes thru the handle and into the head of cable; thus not compatible.

Tools I needed to complete this job:
1. 12v 1/4" drive impact gun. I think it was 7/16" socket (or 3/8) for coroplast bolts.
2. 1/4" ratchet with sockets to replace valve bolts. I forget the size. You can use impact gun (carefully) to remove the bottom 2 valve bolts, but you need a ratchet for the top 2.
3. Channel lock pliers. You need to remove the existing nut (see blue arrow in graphic) and replace with new.
4. Allen wrench for installing cable to valve. Valterra supplies this with each new valve.
5. Phillips head screwdriver to remove valve upper body, see orange arrows in graphic.
6. Dikes to cut steel rod/cable. I found I needed to cut around 2 inches of rod from 72" cable to get it to fit into valve.
7. Tie wraps. I used these a lot to support wires and I loosely hung the new 72" valve cables in as big a radius as I could get.
8. Gloves. THESE I have found to be excellent for both grip and resistance to tearing.
9. Worklight.
10. Not required, but I used THIS tool to cut the coroplast (only around 18 inches for galley gray tank access) but I did not worry about any wire above it (out of sight).

[skllstrm]

Very helpful. I still think I will cut because on my rear kitchen Imagine I have the grey water and the fresh water tanks between the black water tank and the front of the trailer. There are lots of valves, pipes and handles sticking through the coroplast and it tears when I try and remove the foam. I am happy to know the the Valterra can be dropped in to replace the Lasalle. I will report my results in a few weeks, I hope.

[rchasei]

Thanks for putting all this into words and sharing on here. I just had the pleasure of repairing the Lasalle Bristol 1.5” gate valve at the bathroom grey tank on our 2018 Imagine 2600RB. Before we bought it, the cable plunger near the pull handle had been damaged, bent, restricting the plunger from sliding into the sheath... and thus, keeping the gate from closing fully. We took our maiden voyage to a nearby state park and realized after using the bathroom sink that our valve was failing, and our 3” end cap was missing one bayonet fitting, allowing the bathroom grey to seep past onto the ground outside. No biggie. We didn’t shower that weekend and brushed our teeth in the galley grey since it closed properly.

All of the info you provided, @wudwork, helped me decide to drop the belly and change the valve. Upon further investigation, I found that I was better off using a spare (to them) cable that I bought from an RV repair center for $10 USD and just replacing the cable. After reading your post, I was surprised to find cable replacement was a possibility, because in your post you mention it only being possible on Valterra valves. I was happy to see it just took a couple of more steps to take the Bristol valve apart and attach the new cable to the existing gate plunger. I also had to find a new nut to attach the pull handle end of the new cable to the mounting bracket outside the frame (the OEM nut was for coarse thread, and this fixer cable was threaded more finely).

Thanks again for the documentation and insight. Being clear of that first hurdle for only $10 was well worth trolling over these comments for the direction. I only wish I’d found this forum prior to purchasing this trailer. Tons of info on what to look for is provided here. That is thanks to all of the great members. Happy to be involved.

[bigjake392]

Can you tell me where the black tank probes are located ? I would think on the inboard side of the tank. The factory probes need to go. I'm a firm believer of the Valterra Horst Miracle probes. Installed them in 2 previous coaches without one problem. My 2021 2600 RB has been nothing but problems with the black tank probes. Had the thought of just a repairable hole to install new probes versus pulling down the whole rear coroplast piece. Thoughts ?

[traveldawg]

Nice write up. Thanks. And good choice of tape too! That's my go-to for the coroplast.

[wudwork]

"Valterra Horst Miracle". Been there, done that, still not good. The "hood" that goes over top of probe works great as stuff falls past it; now when that sensor goes into the sauce, stuff sticks. When sloshing around while towing, stuff sticks and I had little luck with tank flush sprayer cleaning them as the very hood that protects probe blocks the spray. I am abandoning the thru-wall sensor setup and going with external sensors. Not cheap, but very good build quality and I plan to integrate the output of those sensors over the Victron Cerbo GX so I can monitor from Victron as well as the display that comes with these sensors. Some get a 2nd display and put that in wet-bay so you can easily see it during dumping/filling. HERE is the starting point. The following notes are very date sensitive; this was written 2022-Aug.
1. Garnet made a version of their monitors that have a handoff with the n2k protocol. This was for use in Airstream trailers.
2. Grand Design does not currently use the N2k protocol and are considering the RV-C protocol.
3. While Garnet makes a monitor that has an RV-C protocol handoff, Victron does not currently talk to Garnet sensors via RV-C.

So, here is how to get external tank sensors that can be viewed on Victron Cerbo GX system as well as separate display. You do NOT alter your existing sensors/display in ANY way. This is a totally independent setup.
a. Get the n2k version of Garnet sensor kit. HERE is link.
b. Learn all about how to integrate to Victron per HERE. If no interest in Victron integration, mount display where you can easily use it. If Victron integration, don't mount this display; bury it somewhere and simply use it to convert sensors to n2k and display on Cerbo Gx.
c. The fun part is designing your sensor install locations. The tanks in my GD 2970RL are anything but flat/straight, everything is curved and angled. I worked with Garnet support (excellent !!!) to design a "split" sensor for my greys and black tank. (I am installing (2) "stacked" sensors on each tank). As this setup only has a single gray on the display, I am putting a toggle switch on the display to control which gray I will view.

If I was doing this project in a year, I would not do anything now and wait till the Garnet SOUL is released to general public. That is a screen-less unit that talks RV-C and is less $. That assumes Garnet and Victron finalize how to talk amongst systems.

Can you tell me where the black tank probes are located ? I would think on the inboard side of the tank. The factory probes need to go. I'm a firm believer of the Valterra Horst Miracle probes. Installed them in 2 previous coaches without one problem. My 2021 2600 RB has been nothing but problems with the black tank probes. Had the thought of just a repairable hole to install new probes versus pulling down the whole rear coroplast piece. Thoughts ?

[wudwork]

Sensors are on the drain side of grey and black tanks. See post #6 of this thread, I am abandoning the onboard sensors and installing external sensors. The below pic was taken upside down, backwards and on an angle; then this website rotated it. To help orientate, the orange wire sensor is higher up than the yellow/green wire sensors you see. The yellow/green wire sensors are at the lower (closer to ground) portion of tank. The 2nd pic, you can see one bolt of the 3" drain valve in upper left corner. The wire bundle hangs straight towards ground. I found it very helpful to goto Grand Design parts lookup, get the tank model number for your rig then goto Alpha tank website and get all the technicals for YOUR tank.

Hope it helps.

Can you tell me where the black tank probes are located ? I would think on the inboard side of the tank. The factory probes need to go. I'm a firm believer of the Valterra Horst Miracle probes. Installed them in 2 previous coaches without one problem. My 2021 2600 RB has been nothing but problems with the black tank probes. Had the thought of just a repairable hole to install new probes versus pulling down the whole rear coroplast piece. Thoughts ?