leak at connection to drain pipes and Holding tank

[robrv3]

I have a small leak at the connection to drain pipes and the Holding tank that leaks when I drain a sink. What kind of connection is between the drain pipes and tank. I can unbolt the tank and drop it I think or are these pipes fastened to the tank. I have very limited access to where the drain pipes connect to the tank and not able to inspect that connection very well Any tips or ideas?

its a Chevy 2011 chassis Coachmen Freelander 21QB

Below is an image it's hard to reach and work with, I think I would have to cut the floor in the RV bathroom to work with this pipe




Mod Edit: Corrected image widths so as to not skew the forum window.

[robrv3]

SJ-Chris wrote:
"There are different types of leaks and they have different levels of severity..."


I filled the sink to the top 3 times then pulled the sink plug and no leak. Before anytime a sink was draining a little water would leak


Thanks to everybody for all your help and advice, Thank God I didn't have to drop the tank or pull out the camper shower to rework the plumbing beneath
Chris

[robrv3]

ernie1 wrote:
robrv3, the better way to test the plumbing is to fill your sink as full as you can possibly get it with water and then unplug the drain and watch for leaks. This will make a lot of difference in your results.

I filled the sink to the top 3 times then pulled the sink plug and no leak. Before anytime a sink was draining a little water would leak

[SJ-Chris]

There are different types of leaks and they have different levels of severity...

It could leak in such a way that every time water flows into the sink and to the waste tank you get a leak. This would be the worst kind as it is constant. For example, imagine a pipe that running at an angle (or horizontal) and you have a leak on the bottom side of the pipe....anytime water passes by it will leak.

It could be a leak such that it will only leak if the water level goes above the point where the leak is. For example, imagine a pipe that is running at an angle (or horizontal) and you have a leak on the top side of the pipe....when water runs by it likely won't leak. But if/when the tank (and this pipe) get full then it will leak. This would be a less severe/urgent issue. However, if the leak/crack/hole is big enough you might start getting smells.

One way to test your leak... Start with a clean black waste tank (use your tank flush if you have one). Fill it with water (and a little bleach in case you do get some leaking) until it is 100% full. In theory, you should be able to keep adding water to your toilet until you can see water filling the pipe from your toilet to your waste tank, and then even further until you literally have some water starting to fill your toilet bowl and not going down. At this point, your black waste tank is 100%+ full and the lines from your toilet and also from your bathroom sink will contain standing water. This system is designed to be water tight so if there are no leaks the water will just sit there in your toilet bowl at the same level for hours and hours. If it slowly drains lower, you know you have a leak somewhere.

Note: I've read that some bathroom sinks in some RVs/trailers run to the gray water tank and not the black tank. All of mine run to the black tank.

Anyways...I hope your leak stays plugged. These RVs/trailers are supposed to be about enjoyment...not as much fun when we have to work on repairs.

Happy Camping!
Chris

[ernie1]

robrv3, the better way to test the plumbing is to fill your sink as full as you can possibly get it with water and then unplug the drain and watch for leaks. This will make a lot of difference in your results.

[Roger10378]

I think you fixed it.

Several years ago I had noticed a slight odor from my gray tank when it was about 3/4 full. I figured out that it was coming from where the drain pipe went into the top of the tank. Further investigation showed the the tank had a rubber grommet that the pipe went thru and the floor forced the pipe slightly to the side which deformed the grommet so that it leaked. A few minutes with a Dremel and no more smell. At least I had easy access to the problem area.

[robrv3]

It stopped leaking for now. Using a right-angle drill with a short drill bit and a endo camera taped to the drill so I could see where I was drilling to drill some holes in the 1/4 plywood that pipe goes through then I used a Dremel tool with a right-angle adapter to widen the hole so I can see what's going on and maybe apply some kind of sealant. But then when I ran water down the drain and observed that pipe there was no leak. Maybe the material I removed released some pressure but if it leaks again maybe I can do something about it

[Mayor30]

Years ago,I broke off the dump valve when it caught on a tree stump.It also cracked the connection where the drain line came out of the tank. I used JB Weld apoxy. I cleaned off the crack in the tank and mixed and applied the JB weld per the instructions. It lasted for the over 2 years and then I sold the trailer.I have used JB Weld on different things both plastic and metal and it always worked for me.

[valhalla360]

5th wheel not motorhome but on a previous RV, had a similar leak. It was the tank cracked around the fitting, which was glued into place with no real option for replacement. There was a special glue (need to match the correct plastic) which basically melted it back together.

[robrv3]

It's a Chevy 2011 chassis Coachmen Freelander 21QB don't know if there is a plate somewhere in the vehicle with more information. There is a panel I can remove that gives me limited access. Your photos were helpful I can see I cant simply unbolt the tank and drop it it looks like my best bet at this point is to apply some sort of sealant around the pipe as it passes through plywood to the tank

[SJ-Chris]

Please let us know the year, make, and model of your RV and I'm sure someone will be able to give you some great/specific info.

I have a 2015 Thor Majestic 28a Class C RV. I had a leak recently on my black waste tank line (from the toilet to the waste tank where it connects). I also had to deal with the waste line from the bathroom sink to the black waste tank in the process. I posted a detailed description of the project with photos of every step. It shows the steps involving the sink line going into the black tank so maybe it will give you some ideas.

https://www.rv.net/forum/index.cfm/fuseaction/thread/tid/30326133/gotomsg/30326133/p/1.cfm#30326133

In the above link, scroll down to post ~#10 for the detailed description with photos.

The key piece of info that would have saved me hours (and might save YOU hours) is that the job required removing the rear wheel well insert. That gave me complete access to all the pipes going to the black waste tank (....maybe YOUR RV will be the same).

Step #1: Clean out your black tank as best as you can before you start!

Let us know. Good luck!
Chris