Waste Valves Restoration and Upgrade

[jd1923]

There was a recent thread started by @Galileo where Val had a black tank waste valve beyond repair. OTT Service suggested replacing the valve with the Valterra motorized valve which would eliminate the need for the 12 ft pull cable replaced by an electric switch.

This got me thinking as we have a 10-year-old hull and ALL three (3) waste valves, including the 1 1/2" gray valve for the bathroom, are very difficult to pull the valves open and to push back to close. It's always better to work preventive maintenance than to get caught on the road with a stuck waste valve!

I wanted to install electric motorized valves in all 3 locations but we were made aware by OTT (through Val's service call) that replacing the gray valve would be difficult. From a picture I had taken of that area, I noted it was installed laying flat on the hull floor which would not allow for the considerably wider motorized valve.

I couldn't see a design with one manual valve with t-pull handle in the rear next to an electric switch for the other. So my plan morphed into restoring the main waste valves replacing OEM parts as needed. I kept the idea of a motorized 1 1/2" valve for the bathroom because this valve must be opened/closed often, every travel day. What a chronic pain it is getting into the bathroom, reaching down ankle height and pulling the valve open before pulling a muscle! Yep, we're getting older...

To start, I removed both valves under the front dinette seat. The 3" black and the 1 1/2" gray valves were originally installed angled towards and touching each other, with the gray valve jammed against the fiberglass wall. I sawed off the 1 1/2" ABS at the waste valve flange so that larger motorized valve could be installed. Purchase of a new flange and two couplings was all that was needed, as I was happy we had some ABS glue. With the plumbing out it was so easy to run wiring for our DC-DC charger from the hitch to rear dinette seat, an added bonus.

At first, I wanted to install the power switch near the entrance door so that it could be reached while standing outside. Thinking through the extra work and that it could be easily damaged or switched accidently, I installed it right there under the dinette seat. Here the provided wiring harness reached the buses under the rear dinette seat w/o modification. I cut a tight-fit rectangle opening for the switch alone, tossed the large faceplate and by-passed the odd fuse/reset button, adding a 5A fuse at the +bus. When the valve is open a thin red LED shows which can be seen from outside the entrance door. It is soooo great to merely press a button to work this valve!

[jd1923]

A bench inspection of all 3 valves showed something quite interesting. With cables detached, the black waste valve opened and closed easily yet the seals were crusty and looked more worn. The seals on the gray valves looked to be in better condition yet the valve mechanisms on both gray valves were stuck, all gunk-ed up!

My thinking is soap and/or tank additives in the gray plumbing caused this and the black tank is certainly a different chemistry. I cannot be sure with 3 prior owners of our hull what was used through the years. I remember our good friend Steve @ScubaRx writing that he does not use additives, has not for years, and I believe we’re going with that plan going forward.

I was so hoping not to have to replace the gray waste valve since I had installed our Victron MP2 directly over it. Last week I reached down and around the inverter and with much pain and patience. I loosed the Allen key on the cable and the two Phillips screws to remove the sheath. With the cable detached I found the valve was near impossible to move by hand. What I feared came true, and today with much pain I removed this valve.

Was very happy to get the valve out and in only 2 hours, considering all. First of course, I removed the ground to the batteries and switched off the solar. I had to unstrap the inverter and pull the 42 LB beast up far enough out of the way to work below it. I used a steel bracket to hold it up. I feared I had taped the shelf down strong with the VHB tape, but it popped off with a strong pull due to the slick shelving material.

The waste valve was jammed so hard into the floor that the two bottom bolts were extremely difficult to remove (see impression of the waste valve in the floor insulation in 2nd picture). They were also rusty given their bottom location. You needed two open-ended 7/16” wrenches and the back bolt is extremely hard to reach being under the aisle floor. I spent 30 min on these two bolts alone! I’m really good at wrenching in tight spots from considerable experience. Most of you reading this, I strongly suggest getting OTT to replace this valve when you feel "it’s time." If they charge more than a hour labor, a good retort would be, “Well you put it there!”

There was a rubber mat installed under the gray tank which was halfway under the waste valve. I cut this rubber out in the area where the valve is bolted to make the reinstall a little easier. The gray valve was much worse than the picture reveals and the fact that this valve was installed horizontally makes all the residue collect on the lower side causing friction on one side adding to overall pull & push resistance.

I replaced entire valve assembly for the gray and just the seals on the black. The gray pull cable is about 4' short and looks fine with a slight curve. I will replace the 144” black cable when it arrives. Before we travel next week, I’ll get the garden hose in the Oliver, fill the black and gray tanks some, run water into the shower drain to test all 3 valves.

Tomorrow I should install the new gray valve. It will not be easy as the two flanges do not sit parallel. The two bottom bolts will be fun again! Then I need a plug and some fiberglass repair for the hole in the bathroom wall, and I'm sure I'll see other needs.

Sure hope to be good very soon... and for another 10+ years!

Edited Thursday at 07:42 AM by jd1923

[johnwen]

20 hours ago, jd1923 said:

a good retort would be, “Well you put it there!

[Galileo]

On 2/20/2025 at 12:35 AM, jd1923 said:

Yep, we're getting older...

You may well be getting older (glad it’s only you 😂 ) but it sounds like you’ve got a good amount of get-up-and-go left in you with that description of the work you did!

On valves -

We have the “Autovent” option for the gray water “fill” from the factory. Keeps the grey water out of the shower pan while moving.  Oliver installs the switch in the closet with a spring-loaded open/close rocker switch. We remember to open/close it -most- of the time. I suppose even it will need seals replaced eventually. Then again, unless it’s a dramatic failure, I don’t think it’s as critical as the dump valves.

Grey tank dump - that T handle moved quite easily. Short cable. Hopefully it will last us the ten years yours has. Maybe it will be the next owner’s problem. I have no plans to upgrade it to electric.

Blank tank dump - I think that horse is dead. I’m dismounting.

Tank Additives -

We usually use an odor-control additive in the black tank. Only occasionally in the grey tank. I really miss the good old Thetford blue stuff. It was quite effective and actually made the black tank dumping smell kinda good. I think it was the same stuff they use(d?) in commercial ports-potties. Pretty sure it had formaldehyde, so mere mortals prolly can’t obtain it. 

My current favorites are Thetford Aqua Max “Summer Cypress Scent”. It smells nice. Downsides are I think they’re optimistic about one packet treating 40 gallons…. That, and it doesn’t dissolve completely. Leaves some grainy specsks behind. (I dissolved on in a clear container with plenty of warm water.) I’m also leery of the packets. I think they’re some kind of gelatin, and I’ve found they don’t dissolve completely either. That said, I probably won’t buy them again.

The Camco TST liquid seems the safest bet to me. Nothing to clog up or be left behind.

As for my least favorite, “Happy Camper” gets the nod. I can’t understand the raves on Amazon. The stuff doesn’t dissolve easily, and tends to harden like plaster! Looks like an invitation to gunked-up valves! That, and I find it has about zero odor control. I have half a bucket of it left that I’ll donate to a non-discerning RVer.

As for valve lubricants and treatments, I’ve tried the Thetford valve lubricant to try to help my black tank valve - and it did nothing. Probably because it was the cable, not the valve. 
 

Anyway, I suppose you can get away with using no additives at all - but emptying the black tank (and even the grey tank) are gonna be a smelly adventure!

 

[Galileo]

12 hours ago, johnwen said:

That reminds me that there are a few automotive designers that need to be slapped around a bit…..

Having to pull an engine to change a spark plug sounds like a good reason for capitol punishment.

One shouldn’t need to be double jointed and have eyes on one’s fingertips to do periodic maintenance on any device. 
 

That said your suggestion of “well you put it there” is unlikely to phase anyone. 

[jd1923]

22 minutes ago, Galileo said:

That reminds me that there are a few automotive designers that need to be slapped around a bit…

Thought this same thing soooo many times! Like changing the starter motor of a 4WD Gen2 Toyota 4Runner or pulling the PS pump (known for leaking) on my Lexus SC400.

Can I add replacing the fuel pump in our TV - pull the fuel tank or remove the truck bed? I went with the latter. These are jobs I've done in only the last two years and I cuss design engineers that only care of manufacturing process with no concern for maintenance.

Auto design engineers should be made to work an internship in service for 3 years before allowed to make one design decision! The 3" gray plumbing should have been installed 1/2" off the floor instead of pushing so hard on the floor to make an impression into the insulation! Also defeats the purpose of the insulation.

Edited 14 hours ago by jd1923

[jd1923]

On 2/19/2025 at 11:35 PM, jd1923 said:

I wanted to install electric motorized valves in all 3 locations but we were made aware by OTT (through Val's service call) that replacing the gray valve would be difficult. From a picture I had taken of that area, I noted it was installed laying flat on the hull floor which would not allow for the considerably wider motorized valve.

I couldn't see a design with one manual valve with t-pull handle in the rear next to an electric switch for the other.

Wanted to provide an update on this statement. Just yesterday, in another post on this subject, I learned of Drain Master waste valves. This product is flush on one side, so it can be installed directly on the floor in the gray tank waste valve location. Looks to be a very good option when anybody needs a new gray waste valve.

https://drainmaster.com/rv/product/pro-series-s3vt-kit-2-valves-6002

[topgun2]

I haven't followed this thread totally and if someone has mentioned Molykote 111 compound by DuPont I apologize.  HERE is a video on the subject and I believe that it is available on Amazon HERE.

I've not personally tried it on my blade valves and seals nor on my toilet seal.

Bill

[jd1923]

Was a long day getting the new gray waste valve installed.
But by 5PM today... it's done finally, yay! 😂

It's difficult to get the valve in place, in tight quarters, without the rubber seals slipping. The valves in the front have rubber couplings which can be removed giving so much room, but not down here. I applied a sealant on the back side of the rubber seals and set them on the flanges the day before hoping that would keep them in place. One slipped off but the other stayed which certainly helped.

The two flanges were on different angles, tied down by the weight of the 3" gray plumbing on one side and the gray tank on the other. Pulled a long crowbar to raise and shift the plumbing over, used a longer bolt to get one corner started. Installed one part at a time as the full valve assembly would not fit being crammed into the floor. Got everything torqued down, "good-n-tight" after another hour or more...

Removed the old cable to install the new one. You can only source 6 ft cables and must cut them down to fit. OTT installed a stock 3 ft cable. I found it to be jammed up in a corner for being too long. I cut the new cable sheath to 32" and the pull cable 4 3/4" longer. I also cut into the shelf that extends in the rear trunk area of the Oliver using a handheld coping saw, so that the pull cable would have a straight line to the valve (notice bottom left of picture).

So all was good, ya think, but the thin SS steel cable would not fit into the push rod of the valve, the fixture which holds the cable with an Allen key. I tried and tried and then I got a thin needle tool and found that the opening was defective, made in Mexico POS, and mostly closed. In the bottom of the basement, valve installed, I had to drill an opening into the cable receiver using a 90 degree extension powered by a 1/4" impact tool (whoa, make sure yours is good before installing)! 🤣

New waste valve, new pull cable nicely realigned and this valve now opens and closes like butter, so nice!

Tomorrow the 12' cable for the black valve should be delivered. I will also fill tanks to test all three valves tomorrow. Hopefully no leaks but given Murphy's Law, new plumbing often leaks somewhere on first try. I need a break on this project and hoping for the best! Hopefully we're done tomorrow so we can start the fridge, pack clothes and tools, hitch up and be ready for the next adventure! 😂