1992 35' Excella black-water tank leaking

[Doug C]

1992 Excella 25'

I'm getting a leak from my black-water holding tank. The tank will hold 10 gallons without leaking. Somewhere between 10 and 15 gallons it starts to leak. It's a slow leak that just drips out the corner of the sheet-metal box that covers the holding tanks under the trailer. Any ideas would help. I don't want to rush and remove the entire 4'x5' sheet metal box from the bottom of the trailer if that's not necessary. I can cut an inspection hole and try to figure it out, but I'm not sure exactly where to cut it. I'm hoping someone who has had this problem can steer me in the right direction.

Thanks.

[Doug C]

That's actually a 25' Excella. Typo. Thanks.

[damonbeals]

Our 1998 had the same issue and it was the fitting between the tank and the valve. I had to cut a big hole in the pan to again access. Took several hours and isn't a fun job.. Go ahead and order two and do both the Gray and Black at the same time. The part we needed Waste tank slip-in adaptor 0310107 [0310107] - $6.95 : Out-of-Doors Mart!, More Airstream Parts on-line than anyone!

The original in ours was made out of a white plastic and it was cracked and aged, this new part is ABS and shouldn't fail in the same way.

Damon
#4827

[Doug C]

Originally Posted by damonbeals

Our 1998 had the same issue and it was the fitting between the tank and the valve. I had to cut a big hole in the pan to again access. Took several hours and isn't a fun job.. Go ahead and order two and do both the Gray and Black at the same time. The part we needed Waste tank slip-in adaptor 0310107 [0310107] - $6.95 : Out-of-Doors Mart!, More Airstream Parts on-line than anyone!

The original in ours was made out of a white plastic and it was cracked and aged, this new part is ABS and shouldn't fail in the same way.

Damon
#4827

Thank you for the response. Appreciated!

[Doug C]

Originally Posted by damonbeals

Our 1998 had the same issue and it was the fitting between the tank and the valve. I had to cut a big hole in the pan to again access. Took several hours and isn't a fun job.. Go ahead and order two and do both the Gray and Black at the same time. The part we needed Waste tank slip-in adaptor 0310107 [0310107] - $6.95 : Out-of-Doors Mart!, More Airstream Parts on-line than anyone!

The original in ours was made out of a white plastic and it was cracked and aged, this new part is ABS and shouldn't fail in the same way.

Damon
#4827

I decided to start by cutting an inspection hole in the sheet metal under the connection that you describe. I can't see a crack in that piece you mention, but it does look like the area of the leak. Do you know of a video or description of the steps to take to remove and replace this part? At this point, with a hole about 7"x8", I can't tell how to go about taking it apart in the right sequence. Did you cut one big hole in the sheet metal to access both grey and black connections, or two separate holes? How big of a hole in the sheet metal do you think is needed? I'd be grateful for any tips or advice from anyone who has done this repair. I'll also do some Google searches for more info.

Thank you,
Doug

[Doug C]

Originally Posted by Doug C

1992 Excella 25'

I'm getting a leak from my black-water holding tank. The tank will hold 10 gallons without leaking. Somewhere between 10 and 15 gallons it starts to leak. It's a slow leak that just drips out the corner of the sheet-metal box that covers the holding tanks under the trailer. Any ideas would help. I don't want to rush and remove the entire 4'x5' sheet metal box from the bottom of the trailer if that's not necessary. I can cut an inspection hole and try to figure it out, but I'm not sure exactly where to cut it. I'm hoping someone who has had this problem can steer me in the right direction.

Thanks.

Thanks for the good feedback. I ended up replacing the gate valve and the slip-in adapter with new parts from Vintage Trailer Supply. The problem has been fixed. I took the recommendation in my owner's manual, and cut a square hole about 12"x12" in the bottom of the trailer right under the valve to access it.

Below are the notes I put in my database. Maybe this info will help someone else. These directions assume you have already cut the access hole. My valve was Thetford #08709. Your parts and process may vary. My trailer is a 1992 25' Excella.

For black tank gate valve removal: Jack up high, remove sheet metal access cover, rinse out black tank super well and drain overnight, undo three hose clamps, drill out rivet holding extension rod, remove four big Phillips screws that hold valve to slip-in adapter. Valve with plastic elbow and rubber joint will now pull free. Next work the slip-in adapter free from black tank. (Have new o-ring on hand for between valve and adapter. Can rebuild gate valve with new seal and gasket inside if desired. Valve repair kit is VTS-616 Thetford PN 09872. New valve is VTS-814. Adapter is VTS-139.) Clean everything. Re-assemble. Use 100% silicone on slide-in adapter. Adapter in first with clamp on, then valve with elbow and rubber coupler. Don't forget to line-up everything including pull-rod. Need 1/4 drive 7/16 deep socket and 5/16 regular socket, Phillips bits 2 and 3 with adapter to use with ratchet, open 7/16 wrench.

[truxpin]

Thanks for the detailed info Doug. Sorry to drag up an older post , but I'm having the same issue on my '01 Limited black tank. (no leaks or smells untill about 1/2 full or so, then dripping from corner of pan and bad odors! )
So, in reading your posts I have a question.... In lieu of dropping the entire pan (which looks, maybe easy enough being that its held up with bolts and not rivited. But it's one BIG piece) I thought I'd go the access hole route.
So what & how did you cut the hole with? Is there enough clearance to use something like a jig saw? Maybe using an angle gringer and a metal wheel?
Wondering if you can provide any details about location of the access and how you cut it.
Thanks in advance, Todd.

[Doug C]

Yes. I'd be happy to send you what I have. Send me a PM with your email. I have a picture or two I can send, also. Later today I'll try to send you some info. Don't use a jigsaw.