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Lumatic · 08-09-2016, 03:57 PM

Been having a steadily increasing black water leak. Started off just near the discharge pipe, but now will leak out of the belly pan across the whole rear. Took off the banana wrap today. There is no way the leak can be coming out of the valve and leak across the whole back belly pan as the frame is in the way. If I fill the black tank all liquid leaks out without pulling the dump valve. Maybe a gasket between black tank and valve? Maybe a cracked black tank? Ideas/ suggestions?

PS Valve photo is upside down. I will repost.

Lumatic · 08-09-2016, 04:12 PM

3 timesis the charm, I hope. Photo keeps ending upside down. So stand on your head if this still is not right.

The valve is a Thetford, Since it has to come out anyway, I will replace with a new Valterra. Also no grey tank in this baby.

dbj216 · 08-09-2016, 07:32 PM

Now that you have a bit of visibility with the banana wrap off, fill your black tank with fresh water and grab your flashlight. Maybe you can see where it might be dripping.

I think your trailer has an above floor black tank. I suspect it may be cracked. Replacing it will be a big project.

David

A W Warn · 08-09-2016, 07:47 PM

It looks to me like the piece of plastic pipe (the tee with the flange) just below the valve is separated from the valve. It looks like the fasteners are loose. Not sure it that is contributing to the problem, but I would not be surprised.

Also check the tightness of the clamp bands on the rubber coupling. There is pressure there when you open the valve.

Lumatic · 08-09-2016, 07:58 PM

It is an above the floor tank.

The valve body does not appear to be leaking.

Now that I blew off all the muck I will fill the tank tomorrow and see if I can get a better idea where the leak is.

There is also an about 1/2" ID line next to the valve. Anyone have a guess what it is for.

One positive, very little rot in the subfloor, only surface rust on the frame, outrigger and rear plate, for a 71.

sealaker · 08-09-2016, 08:21 PM

I had the same thing....leaks coming from the belly pan ... convinced it was a black tank crack. After having to special order a black tank from Jackson Center and shipped down to Florida...I found out it was my Thetford valves...Both... Black and Grey Tank Valves. Airstream was kind enough to take the tank back, but did have to replace the valves and brackets. I did go back with Thetford Valves. All fixed and belly pan back up. Looked as if the previous owner had let it go through the winter without draining as both valves were cracked. Big project, but learned a lot.

dbj216 · 08-10-2016, 06:40 PM

I believe that 1 1/2 inch drain pipe below your dump valve is the gray water drain. The 71s did not have a gray water tank. You can hook a slinky to your drain port and drain gray water to the sewer hook up, or you can drain it to a portable waste water tank and wheel it to a dump station. But folks no longer drain gray water on the ground.

Fill your above floor black tank and see what happens.

Good news on your subfloor and frame inspection. Many of these vintage trailers suffer from moisture damage in the form of rot and rust. Mine did.

David

Lumatic · 08-10-2016, 08:20 PM

Quote:

Originally Posted by dbj216

But folks no longer drain gray water on the ground.

Like a lot of things, depends.

Lumatic · 08-10-2016, 08:35 PM

I have tried at least 6 times to attach the photo right side up. No matter what I do, including retaking the photo it is upside down. The photo was taken right side up.

TG Twinkie · 08-10-2016, 10:18 PM

Have you tried rotating your phone or camera? Then take the photo.

CRH · 08-10-2016, 11:31 PM

I bet the adapter between the valve and tank has cracked....Both of mine cracked from age last summer.

Dingo Girl · 08-11-2016, 03:50 AM

My photos are always upside down. I have to crop them just a bit, save that copy and then that will post correctly for me.
You could try that.
Plumbing is next on my list so I will be watching what you do here.
Good luck!

ROBERT CROSS · 08-11-2016, 04:03 AM

..... hate it when that happens...sore neck.

Above floor....is the floor wet & stinky?

Grey tank hose & clamps

Bob

Lumatic · 08-11-2016, 08:54 AM

Thank you Cloudsplitter for correcting the view of reality.

Yes, tried rotating and retaking image. Upsy Downsy might be related to a new photo program.

Floor is dry but odor coming up from the tank area. No grey tank. No apparent grey water hose leaks.

Will pull the dump valve next. No apparent leaks from valve body, But a leak in the adapter (as mentioned by CRH and Sealaker above) could be the problem. Will keep you posted. Signing off for now as my dog insists on helping me type.

Lumatic · 08-12-2016, 05:27 PM

OK. Got the dump valve removed.

1.Found a 2+ inch crack in the black tank extending from the dump hole. I can pretty easily get at it. I think I can seal it using something like Flex Seal. I did the same thing about a year ago on my fresh water tank and it is still holding.

2.The mounting flange between the dump valve does not want to easily come out. I don't want to force it and do more damage to the crack I found. Looks like there is a ring inside the flange body. Should I cut it out? Other suggestions?

3.The surrounding subfloor is a little punky around the edges, but not completely rotten. I will use a penetrating epoxy like Rot Doctor which I have used successfully before.

4. Can anyone identify the small black hose next to the mounting flange?

See attached photos.

dbj216 · 08-12-2016, 06:42 PM

It's good you found the source of the leak.

I understand 3M makes an adhesive kit for polyethylene tanks. You might research it on the internet. Sealing cracked polyethylene isn't just real easy. It is a thermoplastic material and it can be "welded", but that takes some experience also.

All I can imagine the 1 1/2" black hose connector is for the gray water drain. Maybe you can turn on the kitchen faucet and see if any water comes out this pipe?

David

Lumatic · 08-12-2016, 06:56 PM

Quote:

Originally Posted by dbj216

All I can imagine the 1 1/2" black hose connector is for the gray water drain. Maybe you can turn on the kitchen faucet and see if any water comes out this pipe?

David

Yes the 1 1/2 is grey water.

There is a small diameter black hose near the valve mounting flange. I don't know what it is for.

HiJoeSilver · 08-12-2016, 07:45 PM

Quote:

Originally Posted by Lumatic

Yes the 1 1/2 is grey water.

There is a small diameter black hose near the valve mounting flange. I don't know what it is for.

Are you sure it's a hose? Could it be the electrical umbilicle running from the bumper to the breaker panel?

Lumatic · 08-13-2016, 08:27 AM

Quote:

Originally Posted by dbj216

It's good you found the source of the leak.

It is a thermoplastic material and it can be "welded", but that takes some experience also.

David

Might not be able to get at the crack to weld it without removing the tank. If that is the case I will replace it. I believe I can get at the crack for gluing.

dbj216 · 08-13-2016, 06:37 PM

Okay, give it a try. The tank is no good the way it is. If the adhesive won't seal it up, you can always replace it.

Maybe your Airstream would like a shinny new black water tank if it comes to that.

David