grey and black valves need replacing, reduce to 1 valve?

[dcorona]

As I prepare for our first trip of the season i noticed that I had a slight drip form the back end of the AS. I already knew the black tank valve was shot but when I traced the leak I discovered that the grey valve is shot as well. Both are original to the AS so this isn't surprising. The leaks are minimal, and I opened up the pan below them so they drip straight down so I am not worried about them until I return.

My question to those who know, Is is worth it togo to one valve of both tanks or am I overthinking it again and just simply replace the valves as it was originally configured.

[SeeMore]

Either way it's a job. Separate valves will keep cross contamination in check, rinse the evacuation hose, and be an easier install than changing piping.

[Moflash]

Very simple and inexpensive fix once the tanks are empty.Less than one hour for both.


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[dbj216]

I recommend a valve for each tank. And I recommend Valterra valves over the Thetfords that may be in there now.

There may be quite a bit of ABS plumbing to do to switch to Valterra valves.

I found it to be a big job to change the valves on my 86.

David

[PaulnGina]

I would stick with 2 valves. If you're at a site that has sewer hook-up, you can leave the black tank valve closed and dump as needed (it's all about "flow" to keep the black tank cleaned out), as opposed to leaving the grey valve open all of the time to drain off the bathroom/kitchen sinks and the shower.

I usually leave both valves closed, but make a point to dump the grey tank very regularly because my wife likes to run lots of water when showering (knowing that we are at full hook-up sites on most trips).

[dcorona]

Originally Posted by dbj216

I recommend a valve for each tank. And I recommend Valterra valves over the Thetfords that may be in there now.

There may be quite a bit of ABS plumbing to do to switch to Valterra valves.

I found it to be a big job to change the valves on my 86.

David

Why switch to Valterra if i may ask.

[dbj216]

Just personal preference. I find the Valterra valves smoother in operation. I like their one piece seal. I like the way the valves bolt together in a sandwich, makes changing seals later easier. And I like the way Valterra offers either male or female connectors on either side of the valve.

I found my old Thetford seals were two piece designs and more complex. I have not looked at a new Thetford valve. And besides, I've been frustrated with the Thetford 3 1/4 diameter bayonet fitting on the outlet of my sewer pipe for years. I could not connect a standard sewer hose or standard cap. I had to go shopping for an adaptor. Made me mad! I was glad to get rid of it.

Lastly, my Thetford SaniCon tank buddy macerator pump was not well thought out in my view. It fit onto the sewer pump parallel, no downward angle for drainage, so their was always a quart of water spilled when I disconnected the pump. And the bayonet years were made of a brittle plastic and broke off the second time I used the thing. I spent two weeks and $30 getting the part replaced, only to have it break again. I found a way to overcome these flaws, but it was a maddening experience.

So it is just personal preference. I'm sure you would be pleased with the Valterra dump valves. I see more Valterra valves at the RV show in town than any other make.

David

[dcorona]

I'll stick to two valves and look at both Thetford and Valterra before i switch them out.

[airdreamers]

Quick fix! Until you decide what you are going to do try this quick fix. I had a slow leak in the gray tank. What I did was buy a Valterra 3" add on valve. Serves me well for now, till I get the ambition to get into the big valve replacement job, or not! Any RV supply store!

See pix!

[Alphonse]

Originally Posted by airdreamers

Quick fix! Until you decide what you are going to do try this quick fix. I had a slow leak in the gray tank. What I did was buy a Valterra 3" add on valve. Serves me well for now, till I get the ambition to get into the big valve replacement job, or not! Any RV supply store!

See pix!

Thanks - good to know, didn't know these were available.

[white laker]

I too jave had a small leak start up on my black tank. I have used valve lube additive and it has stopped the dripping for now. I want to replace the valves, may as well do both, but I need a step by step proceedure to do the job. Any idea as to where I could find one?You tube has some info but not very clear.
Thanks
Pete

[Ag&Au]

I had an annoying slow leak from my black water valve. I had to be sure to have a bucket handy any time I removed the twist on cover. I was all set to begin the laborious task of getting to the valve, but I tried one more thing first. I got a can of WD-40 white lithium spay. I used its attached straw to direct it into the opening the pull handle emerges from. The result was a total lack of leak. My best guess is that the handle linkage was hanging up somewhere due to corrosion and preventing the valve from closing fully.

Ken

[Inland RV Center, In]

Originally Posted by Ag&Au

I had an annoying slow leak from my black water valve. I had to be sure to have a bucket handy any time I removed the twist on cover. I was all set to begin the laborious task of getting to the valve, but I tried one more thing first. I got a can of WD-40 white lithium spay. I used its attached straw to direct it into the opening the pull handle emerges from. The result was a total lack of leak. My best guess is that the handle linkage was hanging up somewhere due to corrosion and preventing the valve from closing fully.

Ken

The Thetford valves have a very long life.

Replacing them sometimes, can take a few hours.

But, replacing them instead of rebuilding them is always the best way to go.

Andy

[Inland RV Center, In]

Originally Posted by dcorona

As I prepare for our first trip of the season i noticed that I had a slight drip form the back end of the AS. I already knew the black tank valve was shot but when I traced the leak I discovered that the grey valve is shot as well. Both are original to the AS so this isn't surprising. The leaks are minimal, and I opened up the pan below them so they drip straight down so I am not worried about them until I return.

My question to those who know, Is is worth it togo to one valve of both tanks or am I overthinking it again and just simply replace the valves as it was originally configured.

Using one valve instead of the 2 that you have, is a HUGE invitation for bacteria to be in the entire gray water system.

DON'T DO IT.

Andy

[TLBIJOU]

Most of the time when the valve leaks it's due to **** stuck in between the seal and the valve. Clean the poop out with a good brush or take it apart and clean it!
Two valves are for a reason as someone else commented on. You dump the black, then gray to flush.
When at a full hook-up the valves should always be closed until they need emptied or you'll get a giant chunk of goop stuck in the tanks. Leaving a campground you should leave several gallons of fresh water in the tanks to slosh around going down the road. This will help keep your tanks clean

[Jacob D]

Interesting comments. Our 67 Overlander has the original Thetford black tank valve which has never leaked. I agree with dbj216 that it is frustrating that standard sewer hose fittings can't be used and Thetford fittings are not always easy to find when needed. I have just learned there is an adapter you can buy that lets you adapt standard to Thetford if you have room for it but I could not find it at either WalMart or Camping World. Amazon is my next try.