71 Black Water Tank Removal

[Lumatic]

Looking for information on removal /replacement of black water tank on my 71 Tradewind. The tank on this model is above floor level. I assume the tank sits on the subfloor and is removed upward from the inside of the trailer? There is no info in my service manual. Thanks.

[takmanii]

I am looking for the same answer.

[HiJoeSilver]

Does the toilet sit on a platform? If it does you've got to remove the toilet then everything that sits on the platform. Then you'll have to remove the platform to get to the tank. Then you'll be able to see how you'll need to remove the vent pipe from the tank. May mean more removal to get that out.

Any upside right photos of the area from the top would help.

[vintagemike]

I have done this repair on our 1971 Tradewind . You have to remove the toilet first. Nots and bolts hold it to the floor flange. The tricky part is that there is a flange under the toilet that you need a special tool for. The flange ring is threaded and you have to rotate it. You will want to tap it with a hammer and screwdriver , but don't do it -you will wreck it! I measured across the flange and had a piece of steel marked for two "blades" welded on. This way you push straight down on the flange and rotate your homemade tool. Worked like a charm.
After the flange is off you can take the rest of the trim off the above floor tank and remove the tank.
BTW. Although the tank didn't leak, I thought this thing is old and eventually will leak and it is a big job to take it out again. I took the plastic tank to a local metal fabrication place and had it reproduced in stainless steel. It worked great and that was nearly 10 years ago. Good luck.

[Lumatic]

[QUOTE=vintagemike;1834617]I I took the plastic tank to a local metal fabrication place and had it reproduced in stainless steel. It worked great and that was nearly 10 years ago. Good luck.[/QUOT]Thanks Mike.

How much did the metal tank cost you?.

I found a problem causing my tank leak. Hopefully the only problem. After pulling the dump valve there is a 2"+ crack in the bottom of the black tank extending from the dump valve hole. I can get at this crack. I have heard there is a 3M polyethylene glue/sealer. I have repaired a similar crack in the fresh water tank with spray on rubber sealant. That was over a year ago and still no leak.

The dump valve was the original Thetford valve, which still does not leak but I will replace with Valterra due to it's age. There is a mounting flange for the valve, maybe similar to the one you described above. (see photo) There is a ring inside the flange which may need to be removed to remove the flange. Do you have any removal suggestions for this flange?

Thanks

[perryg114]

Polyethylene is not something that takes well to gluing but you can weld it. There are some here who have made tanks from plastic and welded the seams. Someone like VTS might have a tank that would fit if you can't repair the one you have.

Perry

[HiJoeSilver]

As mentioned above the toilet flange is threaded into the tank. They're big course threads so generally don't fit super tight. I was able to reach both hands in on opposite dides, turn them outward and grab the flange squeezing top and bottom and get it out. Gloves help get a better grip.