Doing work on the Utility Bay tank plumbing, and really the entire utility bay since you have to take it apart to get the tank manifold.

I want to update that area with new dump valves / 3rd dump valve / replace (or remove) the Javalina / Audit tank sensors. As I got further into it I decided that it would be best to remove all of the plumbing and start somewhat from fresh. Removing the plumbing in front of the dump values is easy enough, just have to get a wrench on the various valve body bolts and it comes apart.
Removing the remaining sections from the tank outlets is more difficult. They are held in place with goop, no no not that, but a flexible butyl sealant and a hose clamp. Twisting the pipe (it does not turn easy at first) loosened the grip of the butyl and then pulled straight out.
First question, searching the forum, it appears the sealant used is something like: BUTYL-FLEX Gutter & Flashing Sealant | DAP Global (https://www.dap.com/products-projects/product-categories/caulks-sealants/specialty/gutter-lap/) Is this what others have used or is there another recommended product?

Next question is, did you reuse the tank insert or get a new one. If you reused it, what did you use to remove any remaining butyl and did you replace the o-ring? If you got a new one, where did you get that part, is it a FT exclusive?
Thanks for your help/guidance!
I never removed that part. My thought on that was if it is not leaking now, I don't want to open up a possibility of leaking when putting back together and there is really nothing that would be worn out. Just my thoughts. Good luck on your project.
I did a complete redesign on my plumbing.
Although the OEM setup worked for decades it just didn't seem like a very good solution to me.
On reply 4, forth image, you can see I used rubber boots that have a hose clamps. No issues with them so far after 4 years.
I don't recall where I purchased them from; maybe from Home Depot. If your interested I can see if I have any records on that.
Utility Bay Redesign (https://www.foreforums.com/index.php?topic=41231.msg410083#msg410083)
I was considering going with a rubber coupling, glad to hear you have had good success using one. Of course I love you utility bay redo!
I did find the original part, its called a Holding Tank Hub Fitting. The description is for transitioning from polyethylene holding tanks to ABS plumbing. 3" female slip end with O-Ring Included.
They recommend a butyl sealant and a hose pipe clamp, just like what was originally there, I've ordered one of these to validate it is the same. You can also purchase replacement O-Rings should you want to clean the old hub.
I received the Holding Tank Hub Fitting, and its exactly what was in place. Icon (what I got) and Drain Master both seem to make the part.
To get rid of butyl from the holding tank outlets, good old Goo Gone worked like a champ. You could also remove the butyl from the existing fittings and use a new O-Ring.
I followed up the butyl removal with a soapy rag to remove any left over Goo Gone solvent, I don't want to any of that left behind when I install the new hubs (and butyl).
A bit more progress today.

Managed to build the plumbing origami to replace the original. By removing the audit tank sensors, I was able to eliminate two threaded joints, and with also 5 glue joints overall. The assembly is about 1.5" less deep as well, not that I can use that space, just the way it turned out.

Put in back in place with the Butyl Rubber and will let it sit for a couple of days before giving it the old leak test. Of course replaced all the valve seals while I was doing everything else.
Great measuring to complete it outside and have the fittings go in the holes of the tank.
Steve,
Were you not able to turn those valves 90* so you could use straight pull/push rods? Are you going to use cables or electric actuators to open/close valves?
Mike
Mike,
They will use cable pulls, those low angles make things pretty smooth to operate.
I did think about turning them and having a straight pulls, especially when the assembly became more compact by loosing the audit sensor plumbing. But in the end decided to go stay with the original arrangement. Now if those tank hubs leak, maybe a revisit ;)
Steve I'm following your post because I need to replace my black and grey valves. Is the outlet of the tanks like a nipple that's extruded from the polyethylene tank and the fitting you have with the O-ring inserts into it? If so then does a hoseclamp go on the outside of that implying that it's somewhat compressible? The photo you've included in your original post shows it but it's covered with plastic so I can't see the details. Also wondering where the butyl sealant goes? Smear it on the fitting before you insert it?
Yes, that is what is there. After I got the old fittings out I placed some some paper towels in the outlet and then placed a ziplock + rubber band over the tank nipple. After a couple of days that area was dry and easy to work on.
Yes ... the tank fitting is somewhat flexible, but the clamp gets tight pretty quick so there is not really much give. It was the MFG of the hub fitting that recommends the pipe clamp and butyl (which is what FT had in place as well)
That is pretty much what I did. I ran a bead in front of the O-Ring, and one behind the O-Ring. The butyl made the fitting slide in pretty easily. I pushed it in and then gave it maybe a 1/4 turn, kind of like what you would do with PVC fittings. I'm going to let it sit for a day to set up (as much as butyl will) before the dreaded leak test!
Been a bit since I posted an update.
The Utility bay has finally been closed up! It was left open this long due to the need to pull cables front to back / side to side and this is the bay that gives the proper access.
The final updates include:
- Changing several components to a black finish: sewer door, outlet, coax/cat, etc.
- The phone cable and coax were updated to Cat6 and RG6.
- Added a Seelevel readout, N2K (NMEA2000 version), allowing the in-coach readout to be shown on the 7" touchscreen which is attached to the Victron Cerbo.
- Added a remote switch and readout for the Progressive surge protector/line monitor. The sibling readout is inside the coach next to the old (and classic) powerline monitor. I reversed mounted these so they are more flush and hide/protect the cables going to them.
- Replaced the hose reel as outlined in another post.
- Replaced the Moen faucet cartridges with NOS from Ebay, the existing ones were a bit crusty.
- Replaced the lighting with LED strip lights
- Added an ABS bottom and back
- Color coded the grey tank pull handle
- Added back a soap dispenser
- Polished that stainless ;)
Don't forget the "spillage dam" ;)
That bay is now almost like a mirror. You could fix your hair while dumping the tanks.
I hope you 2 spend as much time enjoying this coach as you do working on it. :D The wet bay is truly a work of art. I would have to show it to random strangers.
Tom