Tank drain valve

[Steve and Cindy]

The more I go through this old girl the more I find wrong. Tried the plumbing system for the first time. No shut off valve to drain the fresh water tank with and both the grey and black water tank drain valves leak like crazy. How on earth do you change out these valves when everything appears to be glued together (ABS pipe)? Also, what kind of shut off valve is missing from the fresh water tank? There’s just a hole. Van is an ‘88.

 

[TheLooks]

Cant help with the fresh tank drain as I can't tell what they may have used in that hole. The valtera valve can be purchased as the gate only as it can be removed by taking out the 4 bolts leaving the glued in flanges. Be careful not to break the flanges or you will be cutting and glueing. I can tell you that getting everything in place with enough wiggle room, in a non open ended pipe run is no fun.

 

[Steve and Cindy]

Got both Valterra valves swapped out but nowhere on earth have I been able to find the plug for the freshwater tank. Seems to be a very fine thread. Not even a mention of it anywhere.

 

[TheLooks]

Take a better pic on it with a tape measure and maybe we can advise.....

 

[Kevin D Pem]

I replaced mine by removing the bolts that hold the valve to the flange. Not a roadtrek but the valves are standard issue.

 

[Steve and Cindy]

No bolts to be found. And the flange appears to be glued in. No one anywhere knows what goes there. No RV shop. No store. No one online. Google produces nothing. All I can say is that a 3/4” thread in plug seems to go in ok but it leaks like crazy and I can pull it out with my fingers. I guess I’ll have to just glue the thing shut and get creative in installing a new one.

 

[Kevin D Pem]

Fresh water, not abs. Pvc or hdpe try a expanding rubber plug. Or maybe a rubber washer held in place with a toggle bolt.

 

[Steve and Cindy]

Fresh water, not abs. Pvc or hdpe try a expanding rubber plug. Or maybe a rubber washer held in place with a toggle bolt.

An expanding rubber plug sounds like a great idea. Never thought of it. The hole is only about 1/4” or maybe 3/8” deep though. Gonna try it anyway. Thanks.

 

[Steve and Cindy]

Well I tried a rubber expansion plug and it worked for about 5 minutes and then the drip started again.
I also discovered that the water line that goes from the tank to the pump is torn off. Is it possible that what I’ve thought was a drain plug is actually where the water line connects?

 

[Steve and Cindy]

The outlet looks like this. Has very fine threads.

 

[Kevin D Pem]

So, yes! It is the outlet. Your description indicates that the thread has been stripped.

The picture of the bunghole indicates a smaller hole was drilled in the tank in the fitting that was used. (Yes, the universal tanks have bosses welded on so you can best fit).

Now knowing more, this is my suggestion:

Locate a tap & tap drill.
Open the hole with the tap drill (do this by hand. No power tools).
Tap new thread further into the tank..
Use of a pipe with slots on the end will work as a tap.
Put a bunch of Teflon tape on the pipe thread on a plastic pipe nipple, and screw it in.
If you tape right you will be able to use a hot glue gun and glue the nipple to the boss. Then you should be able to use a coupler to reconnect the water line.

Tip:
Make sure you have extra hose so to relieve any pressure on the fitting. Also be sure to tie up to avoid the line snagging in the future.

 

[Steve and Cindy]

The hole seems to have good threads. But they’re fine threads, as opposed to the common course threaded fittings I keep trying. Also, those threads only go in about 1/4”. Then the hole gets much smaller. That inner, smaller hole has a rubber O-ring in it.
I’ve been watching out for other vans like it. I’ll have to just take a peek under one and see what’s supposed to be there. There’s just not too many around here.

 

[Steve and Cindy]

Well I officially give up. LOL. I have been searching for the solution to this issue for a long time. Contacted everyone I could think of. Visited several RV shops. Googled it to death. YouTubed it to death. And nothing. Two days ago I contacted Roadtrek themselves. Can you believe they had no idea? Two different parts guys had no clue about what goes in the drain hole of my tank. They said the fellow at RVlife has extensive knowledge of the older Roadtreks and would definitely be able to help me. But nope. No idea. He even consulted his manager. They sent me pics of what it could be but those solutions would not work. I have also looked underneath 3 other Roadtreks that I have found in my city and none of them have the tank where mine is. Do I have the only 88 Roadtrek with under hanging tanks that was ever made? Sorry for the rant. I’m just so frustrated.

 

[Kevin D Pem]

You are making this too complicated!!!

You have a fill tube.
You have a vent tube.
You have a tube to pump water out.
And you may have/should have a drain valve.

Original is not a thing on an old rig!!!
Plug anything that you don't need, hook up what you do, anyway you can. It is that simple.

 

[Kevin D Pem]

Oh! I had a vintage trailer that I put a hose with a bib fitting onto the drain fitting, to make gravity filling without my attention a reality. You need to make this fun!!! Be creative, enjoy life,,even while you work!

 

[Steve and Cindy]

You are making this too complicated!!!

You have a fill tube.
You have a vent tube.
You have a tube to pump water out.
And you may have/should have a drain valve.

Original is not a thing on an old rig!!!
Plug anything that you don't need, hook up what you do, anyway you can. It is that simple.

Yes I guess I forgot to mention that in my rant. I give up on trying to find this plug and I’m going to try to fit a new tank in it’s place. But the existing tank is an oddly shaped tank that is designed to fit into the cramped space where it is. A plain square or rectangular tank will have to be pretty small to fit there and I’m not putting it inside anywhere. It’s just such a drag to think that all I need is the proper plug for the existing tank which is in perfect condition. Such is life.

 

[Kevin D Pem]

It is a bummer! Can you take it to a place that could weld a new boss on it or plug the hole, so you can save it?