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Topic: Grey Tank Vent (aka air admittance valve) (Read 499 times) previous topic - next topic

Grey Tank Vent (aka air admittance valve)

Our 1996 U320 has an air admittance valve for the grey water system in the cabinet behind the toilet.  That cabinet has also been a great place to store many other things.  One of those must have been the final straw and broke the short stack connecting the air admittance valve to the grey water vent pipes.  The result was an odor that increased with the bathroom vent fan operation.

When I found the source of the problem I was more than a bit concerned about how a repair could be affected.

The first 2 photos show location; the next 2 give an idea for the sinking feeling I had, not sure how I would tackle the repair - no way to re-glue the broken plastic and no easy way to cut out and replace the coupling tee.

The following few photos show how I was able to make the repair (albeit perhaps temporary) once I found that the floorboard was designed to be removed (thanks Foretravel! ).  The rubber pipe joiner was the life saver!


Grant and Betty
1996  U320C  40' WTBI 4949, Xtreme FBP 2011
2003 CRV

Re: Grey Tank Vent (aka air admittance valve)

Reply #1 –
Grant, I don't think you need to concern yourself with that being a temporary repair. Those rubber couplers are very durable, and this one being inside, it will probably last as long as the rest of the coach. Besides, it would be relatively easy to just replace it with a new one. I used a larger version that was inside a stainless sleeve for my third valve installation inside the wet bay. As long as you had a fairly smooth surface for it to seal against, I'd say it's good to go!
Don
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Don & Tys
1999 U270 3602 WTFE #5402
Xtreme Stage 1 w/Headlight, Step Conversion, etc.
2009 Honda Fit Sport with Navi
Freedom is NOT "just another word for nothing left to lose"... with apologies to Kris Kristofferson

Re: Grey Tank Vent (aka air admittance valve)

Reply #2 –
Agree with Don,

Sand off any raised areas (such as markings/lettering) so the rubber has a smooth surface.  Then you should be good to go.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Grey Tank Vent (aka air admittance valve)

Reply #3 –
Thanks Don/Brett; I cut off the worst of it and cleaned it up before the final placement
Grant and Betty
1996  U320C  40' WTBI 4949, Xtreme FBP 2011
2003 CRV
 

Re: Grey Tank Vent (aka air admittance valve)

Reply #5 –
Fernco couplings are durable may last 10 years or more. The no-hub bands with the corrugated stainless steel are used in permanent situations but I'm not sure if you can get them smaller than  1 1/2"
Old Phart Phred, EIEIO
89 GV ored 36' #3405 300 hp cat 3208 ATAAC side radiator, mountain tamer exhaust brake