Broken sink vent pipe

[KDEL1970]

Hey all..

I was wondering if anyone has had a problem with cracking pipes under the kitchen sink area. It looks like they vented the sink to a small vent under my kitchen window near the door. I went out to check the camper for mice today and when looking under the sink, I noticed the elbow clearly broken the gap is over an inch so something must have moved. The wife was complaining about a foul odor toward the end of the season. I think I found it. I would assume this pipe to evacuate bad air from the sink trap and not caused by water freeze. Does this sound like a correct assumption? The floor in front of the stove felt squishy so I plan on dropping the underbelly to see what that is about. Are the two problems possibly connected? There is no sign of water in the cabinets. I plan to get in there with the multi tool and cut out the broken pipe sections. I only want to do the job once and was wondering if anyone has any insight.

Ken

[Mountainmanbob]

for a slight crack in a fitting that is not under pressure
one could
after a little sanding
apply some JB Weld to said crack
save a lot of work
and
should hold fine

sounds like you have two different issues

Mountainman

[KDEL1970]

Thanks.. But it is going to be more work than jb weld. The break is the damnest thing! Oh well it is 5 years old now and the the games are beginning. It has been fairly trouble free except having the both sides replaced after a crack along the top of my small slide. Forest River fixed it free, but I had to take it to the factory. I have attached a photo. The pipe looks like it goes down to the tank and up to the vent. Hopefully with a few cuts, a new wye, some pvc cement and teflon tape I should be in business. It look like the tank is more forward than my squishy floor. Might be another issue.

Ken

[Mountainmanbob]

Originally Posted by KDEL1970

Thanks.. But it is going to be more work than jb weld.

wow
yes I see that JB will not even come close
looks like they put that pipe in with a lot of stress
it broke leaving a large gap

good luck with this one

Mountainman

[cfsoistman]

You may want to add a Fernco Coupling or two to your list. Our old trailer had a drain off the shower break off twice at the threaded connection. Once I replaced the drain and added the rubber Fernco coupling it had flexibility and stayed in one piece for the next 4 years until we traded it in for our Georgteown.

[BarryD0706]

Maybe that bottom pipe goes into a tank and the tank supports have failed, causing the tank to drop down.

[VinceU]

Originally Posted by KDEL1970

Thanks.. But it is going to be more work than jb weld. The break is the damnest thing! Oh well it is 5 years old now and the the games are beginning. It has been fairly trouble free except having the both sides replaced after a crack along the top of my small slide. Forest River fixed it free, but I had to take it to the factory. I have attached a photo. The pipe looks like it goes down to the tank and up to the vent. Hopefully with a few cuts, a new wye, some pvc cement and teflon tape I should be in business. It look like the tank is more forward than my squishy floor. Might be another issue.

Ken

I gotta agree with Charlie, I'd even use a corrugated expansion joint that allows some elongation and compression. Something's moving. And its heavier than plastic pipe can prevent. Joints like that go on with clamps, no pressure to speak of, your just directing air flow up and down.

[KDEL1970]

Thanks all.

So the general consensus is to replace the elbow and use a fernco in the pipe above and the pipe below? I intend on dropping the underbelly to see what is going on in the belly of the beast. There may be something to the shifting tank. May have to drag out the mig welder and get creative. Vince, where would you suggest putting the compression joint? Is it worth also putting a fernco in the horizontal pipe to give additional flexibility or are the more prone to leaking in a horizontal joint? Thanks for all the input. The crappy white stuff they are calling for Wednesday may pump the brakes on my plumbing fix, but on the up side it was mouse free!

Ken

[VinceU]

Originally Posted by KDEL1970

Thanks all.

So the general consensus is to replace the elbow and use a fernco in the pipe above and the pipe below? I intend on dropping the underbelly to see what is going on in the belly of the beast. There may be something to the shifting tank. May have to drag out the mig welder and get creative. Vince, where would you suggest putting the compression joint? Is it worth also putting a fernco in the horizontal pipe to give additional flexibility or are the more prone to leaking in a horizontal joint? Thanks for all the input. The crappy white stuff they are calling for Wednesday may pump the brakes on my plumbing fix, but on the up side it was mouse free!

Ken

I think I would soften the 6" rise above the lateral joint. It seems fine on the horizontal run, just not long enough in the vertical. Leave a 2" nipple above the joint and at the top. Insert your flex pipe between them. Maybe you'll find the cause below and won't need it anyway. Let us know what you find, I've never seen this much stress pipe stress in a camper.

[KDEL1970]

Hey all,

I found my fix and it looks like it should work well. I found a totally rubber Fernco Tee, it is elongated on all ends, and will compensate for the cut abs pipe. I will have to curb the roaming of the undersink pipe with a few pipe hangers and the problem should be fixed. Thanks for all the help I will post a pic of the fix when done.

[VinceU]

Originally Posted by KDEL1970

Hey all,

I found my fix and it looks like it should work well. I found a totally rubber Fernco Tee, it is elongated on all ends, and will compensate for the cut abs pipe. I will have to curb the roaming of the undersink pipe with a few pipe hangers and the problem should be fixed. Thanks for all the help I will post a pic of the fix when done.

Perfect!

[KDEL1970]

It looks like in an idiotic design flaw, the pipe that runs from the sink trap to the tank and vent is not secured at all and moves freely both side to side and up and down. I am assuming it is the constant movement over 4 1/2 years that caused the problem. I think the rubber tee will absorb the abuse without too much issue, and I will try to limit the free movement of the whole pipe.