2019 Windsport Black Tank Leak - Suggestions for repair

sendit2us · 08-15-2021, 10:03 PM

So we are at a campsite and I go to flush the tanks and when I open the bay where the black water tank is and the stench was strong and the inside of the bay was full of .... lets call it liquid. I flushed the tank, sanitized it, washed the inside of the bay dryed it out and drove home. parked in driveway and I filled the black water to the top with fresh water to see if I can locate the leak. Nothing for two weeks. Then.... it started to leak. Thought it was strange (but then again I live in Southern California, and strange is often associated with that.

)
The leak is is coming from a plastic piece (gasket/plug?) in upper right corner of the tank. This is not the sensors. The plastic piece is about the size of a Silver dollar(remember those?) and has two plastic protruding knobs and a metal nut embedded into the plastic in the center. The metal nut has internal threads. Picture is worth a thousand words here....
I guess I could seal around this plastic piece, however that just seems to cover up the issue and not actually fix the issue.
Any Suggestions would be greatly appreciated.
Oh... 2019 Thor Windsport 27B
Thanks!!

**16ACE27** · 08-15-2021, 10:26 PM

So I'm assuming the second picture is sideways.
You can see the level sensors with the attached wires.
It seems you have two of these "ports": one at the top and one at the bottom.
They look similar to your sensor ports but bigger.
Maybe an aftermarket sensor system that has been removed?
Did you purchase the RV new? Or new to you?

cpmath · 08-15-2021, 10:51 PM

I would make up a batch of JP Weld and seal up where it's leaking. That stuff is bullet proof just make sure the surface is really clean and DRY.

dkoldman · 08-15-2021, 11:03 PM

Quote:

Originally Posted by 16ACE27

So I'm assuming the second picture is sideways.
You can see the level sensors with the attached wires.
It seems you have two of these "ports": one at the top and one at the bottom.
They look similar to your sensor ports but bigger.
Maybe an aftermarket sensor system that has been removed?
Did you purchase the RV new? Or new to you?

ACE,

That is a 2019 27B so I know this Coach inside out. It was one that we had thought we actually bought at MHSRV, but PDI fell apart.

His picture is correct orientation, if you look close; you can see the dump valve underneath. It also has the light fixture to the right. It is the Alpha 739RAW tank; so it only holds 21 gallons.

Regardless you are right but the sensors 1/3 full and 2/3 full sensor seem too close together. I never lifted the cover to see the sensors like the OP has. I just recall struggling with the concept of having two separate bays for Gray and Black tanks.

If it were mine, I would try to strip off the sealant and take the plug out and properly reset it with new sealant. It may leak again in another spot. Should not be too hard of a fix. Based on who does it, I would also consider getting another plug and raise the 2/3 full sensor a tad higher or lower the 1/3 full sensor, but Thor must have wanted the RV owner to know when it was truly over 1/3 full; but then warn that it is 2/3 full because it is only 21 gallons?

OP

Your Tank Mfg specs is below...

https://alphallc.us/wp-content/uploads/739002.jpg

https://alphallc.us/products/tanks/

Attached is Black tank bay for 2019 27B I tried to buy.

sendit2us · 08-16-2021, 03:11 AM

Quote:

Originally Posted by 16ACE27

So I'm assuming the second picture is sideways.

You can see the level sensors with the attached wires.

It seems you have two of these "ports": one at the top and one at the bottom.

They look similar to your sensor ports but bigger.

Maybe an aftermarket sensor system that has been removed?

Did you purchase the RV new? Or new to you?

16ace27 . You are correct, the one photo is sideways, and I'm confident the larger one is not the sensor but the one below it is. I purchased new

sendit2us · 08-16-2021, 03:24 AM

Quote:

Originally Posted by dkoldman

ACE,

That is a 2019 27B so I know this Coach inside out. It was one that we had thought we actually bought at MHSRV, but PDI fell apart.

His picture is correct orientation, if you look close; you can see the dump valve underneath. It also has the light fixture to the right. It is the Alpha 739RAW tank; so it only holds 21 gallons.

Regardless you are right but the sensors 1/3 full and 2/3 full sensor seem too close together. I never lifted the cover to see the sensors like the OP has. I just recall struggling with the concept of having two separate bays for Gray and Black tanks.

If it were mine, I would try to strip off the sealant and take the plug out and properly reset it with new sealant. It may leak again in another spot. Should not be too hard of a fix. Based on who does it, I would also consider getting another plug and raise the 2/3 full sensor a tad higher or lower the 1/3 full sensor, but Thor must have wanted the RV owner to know when it was truly over 1/3 full; but then warn that it is 2/3 full because it is only 21 gallons?

OP

Your Tank Mfg specs is below...

https://alphallc.us/wp-content/uploads/739002.jpg

https://alphallc.us/products/tanks/

Attached is Black tank bay for 2019 27B I tried to buy.

dkoldman.... what type of sealant do you recommend? Also where would I go to find a replacement for that plug? Is there a special tool that is needed to remove it?
Sorry for all the questions, dealing with a rookie here.
Lastly, I noticed the same thing you did about the manufacturer and size of tank. Which is VERY interesting because the Thor specs i was given by the dealer say this is supposed to be a 40 gallon tank.

dkoldman · 08-16-2021, 04:16 AM

Quote:

Originally Posted by sendit2us

dkoldman.... what type of sealant do you recommend? Also where would I go to find a replacement for that plug? Is there a special tool that is needed to remove it?
Sorry for all the questions, dealing with a rookie here.
Lastly, I noticed the same thing you did about the manufacturer and size of tank. Which is VERY interesting because the Thor specs i was given by the dealer say this is supposed to be a 40 gallon tank.

I just pulled my paperwork and brochures and it is suppose to be 40 gallon holding tanks for Black and Gray.

Did you buy the RV brand new or did you buy used?

You really should call Thor and have them look up your serial number to see if they have record of what happened? It may explain why your sensors don't seem to be aligned properly. Someone may have repaired with some aftermarket product and they installed a smaller tank? Check your Gray tank to see if it is same size with same labels or larger? Get pictures of everything.

If it is me, the mission has changed. Postpone the leak fix and see if you can't get Thor to explain why you don't have 40 gallon waste tank?. If somehow they confirm it really is the right tank, then you ask them about what sealant they used because it looks to be leaking to you. It is new enough 2019; and serious enough dealing with black waste, they may have a dealer repair for you. Or at a minimum they tell you what you need to DIY.

It is big difference between 21 gal and 40 gals, I doubt the Mfg labeled it incorrectly; which is why I say the tank may have been replaced?

dkoldman · 08-16-2021, 04:42 AM

One other thing I noticed.

The label says you have ...

739RAW
17.5-W x 24-L x 12.5-D RAW Water Tank
21 Gallons

My assumption is you are suppose to have ...

388RAW
18-W x 39-L x 14-D RAW Water Tank
40 Gallons

The 40 gal tanks is 15 inches longer, width is about the same and only 1 1/2 inch taller.

sendit2us · 08-16-2021, 10:26 PM

Quote:

Originally Posted by dkoldman

One other thing I noticed.

The label says you have ...

739RAW
17.5-W x 24-L x 12.5-D RAW Water Tank
21 Gallons

My assumption is you are suppose to have ...

388RAW
18-W x 39-L x 14-D RAW Water Tank
40 Gallons

The 40 gal tanks is 15 inches longer, width is about the same and only 1 1/2 inch taller.

dkoldman - Thanks for all your assistance. After looking into this further based on your suggestions, i noticed under the installation paper sticker installed some stamped info on the tank itself that says Midwest Rotational Molding part no: 749001. I looked this up and it references a 40 gallon black tank. See attached pics.
I have no idea why they would add the other paper sticker on the tank. I'm going to dealer to find out what is going on.

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